Petition for Writ of Certiorari — Damien Guedes, et al., Petitioners v. Bureau of Alcohol, Tobacco, Firearms and Explosives, et al.

TABLE OF CONTENTS

Appendices

A. D.C. Circuit Opinion, Apr. 1, 2019 ........... A1-A97

B. Final Rule, Bump-Stock-Type Devices,

83 Fed. Reg. 66,514, Dec. 26, 2018

(Excerpts) ................................................... B1-B68

C. District Court for the District of

Columbia Memorandum Opinion,

February 25, 2019 ..................................... C1-C81

D. D.C. Circuit Judgment, Apr. 1, 2019 ......... D1-D3

E. D.C. Circuit Order dismissing appeal

No. 19-5043, March 23, 2019 ...................... E1-E2

APPENDIX A

920 F.3d 1

United States Court of Appeals,

District of Columbia Circuit.

Damien GUEDES, et al., Appellants

v.

BUREAU OF ALCOHOL, TOBACCO, FIREARMS

AND EXPLOSIVES, et al., Appellees

No. 19-5042

Consolidated with 19-5044

Argued March 22, 2019

Decided April 1, 2019

Before: Henderson, Srinivasan and Millett, Circuit

Judges.

Opinion

Opinion concurring in part and dissenting in part

filed by Circuit Judge Henderson.

Per Curiam:

*6 In October 2017, a lone gunman armed with

bump-stock-enhanced semiautomatic weapons murdered 58 people and wounded hundreds more in a

mass shooting at a concert in Las Vegas, Nevada. In

the wake of that tragedy, the Bureau of Alcohol, Tobacco, Firearms and Explosives (“Bureau”) promulgated through formal notice-and-comment proceedings a rule that classifies bump-stock devices as machine guns under the National Firearms Act, 26

(A1)

A2

U.S.C. §§ 5801–5872. See Bump-Stock-Type Devices,

83 Fed. Reg. 66,514 (Dec. 26, 2018) (“Bump-Stock

Rule”). The then-Acting Attorney General Matthew

Whitaker initially signed the final Bump-Stock Rule,

and Attorney General William Barr independently

ratified it shortly after taking office. Bump-stock

owners and advocates filed separate lawsuits in the

United States District Court for the District of Columbia to prevent the Rule from taking effect. The

district court denied the plaintiffs’ motions for a preliminary injunction to halt the Rule’s effective date.

Guedes v. Bureau of Alcohol, Tobacco, Firearms, and

Explosives, 356 F.Supp.3d 109 (D.D.C. 2019). We affirm the denial of preliminary injunctive relief.

I

A

The National Firearms Act (i) regulates the production, dealing in, possession, transfer, import, and

export of covered firearms; (ii) creates a national firearms registry; and (iii) imposes taxes on firearms importers, manufacturers, and dealers, as well as specified transfers of covered firearms. 26 U.S.C. §§ 5801–

5861. Failure to comply with the National Firearms

Act’s requirements results in penalties and forfeiture,

and subjects the violator to the general enforcement

measures available under the internal revenue laws.

Id. §§ 5871–5872.

The firearms subject to regulation and registration

under the National Firearms Act include “ma-

A3

chinegun[s].” 26 U.S.C. § 5845(a).1 The statute defines a “machinegun” as “any weapon which shoots, is

designed to shoot, or can be readily restored to shoot,

automatically more than one shot, without manual

reloading, by a single function of the trigger.” 26

U.S.C. § 5845(b). *7 The definition also covers “the

frame or receiver of any such weapon,” as well as

“any part” or “combination of parts designed and intended, for use in converting a weapon into a machinegun,” and “any combination of parts from which

a machinegun can be assembled” as long as those

“parts are in the possession or under the control of a

person.” Id.

Congress expressly charged the Attorney General

with the “administration and enforcement” of the National Firearms Act, 26 U.S.C. § 7801(a)(1), (a)(2)(A),

and provided that the Attorney General “shall prescribe all needful rules and regulations for the enforcement of” the Act,” id. § 7805; see id.

§ 7801(a)(2)(A).

The Gun Control Act of 1968, 18 U.S.C. § 921 et

seq., as amended by the Firearm Owners’ Protection

Act, Pub. L. No. 99-308, 100 Stat. 449 (1986), imposes

both a regulatory licensing scheme and criminal prohibitions on specified firearms transactions. See 18

U.S.C. § 923 (licensing scheme); id. § 922 (criminal

prohibitions). The Gun Control Act incorporates by

reference the definition of machine gun in the National Firearms Act, 26 U.S.C. § 5845(b). See 18

U.S.C. § 921(a)(23). The Gun Control Act also ex1 Except when quoting sources, we use the two-word spelling

of machine gun.

A4

pressly delegates administrative and rulemaking authority to the Attorney General to “prescribe only

such rules and regulations as are necessary to carry

out the provisions of this chapter.” Id. § 926(a).

The Attorney General has delegated the responsibility for administering and enforcing the National

Firearms Act and the Gun Control Act to the Bureau.

See 28 C.F.R. § 0.130(a).

B

1

Machine guns are generally prohibited by federal

law. See 18 U.S.C. § 922(o). On the other hand, many

firearms that require a distinct pull of the trigger to

shoot each bullet are lawful. See generally id. § 922;

26 U.S.C. § 5845.

A “bump stock” is a device that replaces the

standard stationary stock of a semiautomatic rifle—

the part of the rifle that typically rests against the

shooter’s shoulder—with a non-stationary, sliding

stock that allows the shooter to rapidly increase the

rate of fire, approximating that of an automatic

weapon. 83 Fed. Reg. at 66,516. A bump stock does so

by channeling and directing the recoil energy from

each shot “into the space created by the sliding stock

(approximately 1.5 inches) in constrained linear

rearward and forward paths.” Id. at 66,518. In so doing, the bump stock “harnesses the firearm’s recoil

energy as part of a continuous back-and-forth cycle

that allows the shooter to attain continuous firing”

following a single pull of the trigger. Id. at 66,533.

That design allows the shooter, by maintaining constant backward pressure on the trigger as well as

A5

forward pressure on the front of the gun, to fire bullets continuously and at a high rate of fire to “mimic”

the performance of a fully automatic weapon. Id. at

66,516.

Exercising his regulatory authority, the Attorney

General first included a bump-stock type device within the statutory definition of “machinegun” in 2006.

See ATF Ruling 2006-2; see also Akins v. United

States, 312 F. App’x 197, 199 (11th Cir. 2009) (summary order). In later years, some other bumpstock

devices were not categorized as machine guns. 83

Fed. Reg. at 66,514.

2

On October 1, 2017, a shooter used multiple semiautomatic rifles equipped with bump stocks to fire

several hundred rounds of ammunition into a crowd

of concert *8 attendees within a roughly ten-minute

span of time. The “ ‘rapid fire’ operation” of the shooter’s weapons enabled by the bump stocks left 58 dead

and approximately 500 wounded. 83 Fed. Reg. at

66,516.

The Las Vegas massacre prompted an immediate

outcry from the public and members of Congress. See

Guedes, 356 F.Supp.3d at 120, 123. In response, President Trump “direct[ed] the Department of Justice, *

* * as expeditiously as possible, to propose for notice

and comment a rule banning all devices that turn legal weapons into machineguns.” Application of the

Definition of Machinegun to “Bump Fire” Stocks and

Other Similar Devices, 83 Fed. Reg. 7,949, 7,949

(Feb. 20, 2018). The Bureau then revisited the status

of bump stocks and addressed the variation in its pri-

A6

or positions. 83 Fed. Reg. at 66,516–66,517. On

March 29, 2018, then-Attorney General Sessions issued a Notice of Proposed Rulemaking that suggested

“amend[ing] the Bureau of Alcohol, Tobacco, Firearms, and Explosives regulations to clarify that

[bumpstock-type devices] are ‘machineguns’ ” under

26 U.S.C. § 5845(b). See Bump-Stock-Type Devices,

83 Fed. Reg. 13,442 (March 29, 2018).

The Bureau promulgated its final rule on December 26, 2018. With respect to the statutory definition

of machine gun, the Bump-Stock Rule provided that

the National Firearms Act’s use of “the term ‘automatically’ as it modifies ‘shoots, is designed to shoot,

or can be readily restored to shoot,’ ” 26 U.S.C.

§ 5845(b), “means functioning as the result of a selfacting or self-regulating mechanism that allows the

firing of multiple rounds through a single function of

the trigger.” 83 Fed. Reg. at 66,553–66,554 (codified

at 27 C.F.R. §§ 447.11, 478.11, 479.11). The Rule further defined “single function of the trigger,” 26 U.S.C.

§ 5845(b), to mean “a single pull of the trigger and

analogous motions.” 83 Fed. Reg. at 66,553–66,554

(codified at 27 C.F.R. §§ 447.11, 478.11, 479.11).

In light of those definitions, the Bump-Stock Rule

concluded that the statutory term “ ‘machinegun’ includes a bump-stock-type device”—that is, “a device

that allows a semiautomatic firearm to shoot more

than one shot with a single pull of the trigger by harnessing the recoil energy of the semiautomatic firearm to which it is affixed so that the trigger resets

and continues firing without additional physical manipulation of the trigger by the shooter.” 83 Fed. Reg.

A7

at 66,553–66,554 (codified at 27 C.F.R. §§ 447.11,

478.11, 479.11).

In adopting the Bump-Stock Rule, the Bureau relied on both the “plain meaning” of the statute and

the agency’s charge to implement the National Firearms Act and the Gun Control Act. 83 Fed. Reg. at

66,527 (citing and invoking Chevron, U.S.A. v. Natural Res. Def. Council, 467 U.S. 837, 104 S.Ct. 2778, 81

L.Ed.2d 694 (1984) ). The Bureau explained that the

Bump-Stock Rule both “accord[s] with the plain

meaning” of the statute, and “rests on a reasonable

construction of” any “ambiguous” statutory terms. Id.

In the Bureau’s view, by not further defining the

terms “automatically” and “single function of the

trigger,” Congress “left it to the [Attorney General] to

define [them] in the event those terms are ambiguous.” Id. (citing Chevron, 467 U.S. at 844, 104 S.Ct.

2778); see also id. at 66,515 (citing delegations of regulatory authority under 26 U.S.C. §§ 7801(a)(2)(A),

7805(a), and 18 U.S.C. § 926(a)).

The Bureau was explicit that the Bump-Stock Rule

would only become “effective” on March 26, 2019,

ninety days after promulgation. 83 Fed. Reg. at

66,514. The Bureau further assured that individuals

would be subject to “criminal liability only for possessing bump-stock-type devices after *9 the effective

date of regulation, not for possession before that

date.” Id. at 66,525; see also id. (providing that the

Rule “criminalize[s] only future conduct, not past

possession of bump-stock-type devices that ceases by

the effective date”); id. at 66,539 (“To the extent that

owners timely destroy or abandon these bumpstocktype devices, they will not be in violation of the

A8

law[.]”). Bump-stock owners were directed to destroy

their devices or leave them at a Bureau office by

March 26, 2019. Id. at 66,514.

Although most of the rulemaking process occurred

during the tenure of Attorney General Jefferson Sessions, he resigned his office on November 7, 2018.

The President then invoked the Federal Vacancies

Reform Act of 1998 (“Reform Act”), 5 U.S.C.

§ 3345(a)(3), to designate Matthew Whitaker, who

had been Sessions’ chief of staff, “to perform the functions and duties of the office of Attorney General, until the position is filled by appointment or subsequent

designation.” Memorandum from President Donald

Trump to Matthew George Whitaker, Chief of Staff,

Department of Justice (Nov. 8, 2018), J.A. 277. The

final Bump-Stock Rule was signed by then-Acting Attorney General Whitaker. Whitaker served as the

Acting Attorney General for 98 days, until William

Barr was sworn in as the Attorney General on February 14, 2019. See Bump-Stock-Type Devices, 84

Fed. Reg. 9,239, 9,240 (March 14, 2019).

On March 11, 2019, Attorney General Barr announced that he had “independently reevaluate[d]”

the Bump-Stock Rule and the “underlying rulemaking record.” 94 Fed. Reg. at 9,240. “[H]aving reevaluated those materials without any deference to [Whitaker’s] earlier decision,” Attorney General Barr “personally c[a]me to the conclusion that it is appropriate

to ratify and affirm the final rule,” and did so. Id.

C

Three groups of bump-stock owners and advocates

filed suit in the United States District Court for the

A9

District of Columbia to prevent the Bump-Stock Rule

from taking effect. See Damien Guedes v. Bureau of

Alcohol, Tobacco, Firearms, and Explosives, No. 18cv-2988; David Codrea v. William P. Barr, No. 18-cv3086; Firearms Policy Coalition, Inc. v. William P.

Barr, No. 18-cv-3083. As relevant here, the Guedes

plaintiffs (“Guedes”) and the Codrea plaintiffs

(“Codrea”) argued that the Bureau promulgated the

Bump-Stock Rule in violation of the Administrative

Procedure Act, 5 U.S.C. § 500 et seq. Also, the Firearms Policy Coalition (“Coalition”) and Codrea argued that Acting Attorney General Whitaker lacked

the legal authority to promulgate the Rule because

his designation as Acting Attorney General violated

the Attorney General Act, 28 U.S.C. § 508, and the

Appointments Clause of the Constitution, Article II,

Section 2, Clause 2.

The district court denied all three motions for a

preliminary injunction. Guedes, 356 F.Supp.3d at

119. The district court concluded that Guedes,

Codrea, and the Coalition had not demonstrated a

likelihood of success on the merits. The court first

held that “[m]ost of the plaintiffs’ administrative law

challenges are foreclosed by the Chevron doctrine,”

and the Rule “adequately explained” the agency’s decision to classify bump-stock-type devices as machine

guns. Id. at 120. As to the challenges to Whitaker’s

authority, the district court held that the Reform Act

permits the President to deviate from the line of succession that the Attorney General Act provides, subject to certain statutory limitations that indisputably

were satisfied with Whitaker’s appointment. Guedes,

356 F.Supp.3d at 120–121. The court also rejected the

A10

Coalition’s and Codrea’s Appointments *10 Clause

challenge as “foreclosed by Supreme Court precedent

and historical practice.” Id. at 121.

Guedes, Codrea, and the Coalition all appealed.

But none of them sought a stay or an injunction

pending appeal. They chose instead to seek highly

expedited disposition, which this court granted.

While the appeal was pending, Attorney General

Barr ratified and individually endorsed the final

Bump-Stock Rule. At the post-argument request of

the Coalition, we voluntarily dismissed its appeal.

Order, Guedes v. Bureau of Alcohol, Tobacco, Firearms, and Explosives, No. 19-5042, 2019 WL 1398194

(March 23, 2019) (per curiam). But because Codrea

presses the same challenge to Whitaker’s authority to

promulgate the Rule as the Coalition had raised,

Codrea Br. 20–21, that issue remains before us in reviewing the district court’s denial of a preliminary injunction.

II

A preliminary injunction is “an extraordinary

remedy that may only be awarded upon a clear showing that the plaintiff is entitled to such relief.” Winter

v. Natural Res. Def. Council, Inc., 555 U.S. 7, 22, 129

S.Ct. 365, 172 L.Ed.2d 249 (2008). The plaintiffs bear

the burden of persuasion in seeking preliminary relief. Cobell v. Norton, 391 F.3d 251, 258 (D.C. Cir.

2004). Specifically, Guedes and Codrea must establish that: (1) they are “likely to succeed on the merits”; (2) they are “likely to suffer irreparable harm in

the absence of preliminary relief”; (3) the “balance of

equities” tips in their favor; and (4) “an injunction is

A11

in the public interest.” Winter, 555 U.S. at 20, 129

S.Ct. 365; accord Aamer v. Obama, 742 F.3d 1023,

1038 (D.C. Cir. 2014). The last two factors “merge

when the Government is the opposing party.” Nken v.

Holder, 556 U.S. 418, 435, 129 S.Ct. 1749, 173

L.Ed.2d 550 (2009).

We review a district court’s denial of a preliminary

injunction for an abuse of discretion, but in doing so

we review the district court’s legal conclusions de novo and any findings of fact for clear error. Serono

Labs., Inc. v. Shalala, 158 F.3d 1313, 1318 (D.C. Cir.

1998).

III

A foundational requirement for obtaining preliminary injunctive relief is that the plaintiffs demonstrate a likelihood of success on the merits. See Nken,

556 U.S. at 434, 129 S.Ct. 1749 (“The first two factors

of the traditional standard [i.e., likelihood of success

on the merits and irreparable injury] are the most

critical.”); Sherley v. Sebelius, 644 F.3d 388, 393 (D.C.

Cir. 2011) (raising the possibility that “likelihood of

success is an independent, free-standing requirement

for a preliminary injunction”) (quoting Davis v. Pension Benefit Guar. Corp., 571 F.3d 1288, 1296 (D.C.

Cir. 2009) (Kavanaugh, J., concurring)).

Neither the challenge to Acting Attorney General

Whitaker’s authority nor the objections to the substantive validity of the Bump-Stock Rule clears that

hurdle. And because the plaintiffs have shown no

likelihood of success on the merits, we choose not to

“proceed to review the other three preliminary injunction factors.” Arkansas Dairy Coop. Ass’n v. Unit-

A12

ed States Dep’t of Agric., 573 F.3d 815, 832 (D.C. Cir.

2009).

A

Codrea levels a broadside attack on the rule as

categorically invalid because Acting Attorney General Whitaker allegedly lacked the legal authority to

approve the Bump-Stock Rule’s issuance. Specifically,

Codrea argues that Whitaker’s designation *11 to

serve as Acting Attorney General violated both the

Attorney General Act, 28 U.S.C. § 508, and the Constitution’s Appointments Clause, U.S. Const. Art. II,

§ 2, cl. 2. Whether or not those arguments would otherwise have had merit (something we do not decide),

Codrea has no likelihood of success on this claim because the rule has been independently ratified by Attorney General William Barr, whose valid appointment and authority to ratify is unquestioned.

The Appointments Clause requires that “all * * *

Officers of the United States” be appointed by the

President “by and with the Advice and Consent of the

Senate.” U.S. Const. Art. II, § 2, cl. 2. This requirement is the “default manner of appointment,” Edmond v. United States, 520 U.S. 651, 660, 117 S.Ct.

1573, 137 L.Ed.2d 917 (1997), with the only exception

being that Congress may vest the appointment of “inferior Officers” in “the President alone,” “Courts of

Law,” and “the Heads of Departments,” U.S. Const.

Art. II, § 2, cl. 2.

One stark consequence of this scheme is that “the

responsibilities of an office * * * [can] go unperformed

if a vacancy arises and the President and Senate

cannot promptly agree on a replacement.” National

A13

Labor Relations Bd. v. SW Gen., Inc., ––– U.S. ––––,

137 S.Ct. 929, 934, 197 L.Ed.2d 263 (2017); Buckley

v. Valeo, 424 U.S. 1, 132, 96 S.Ct. 612, 46 L.Ed.2d

659 (1976) (per curiam) (“[A]ll officers of the United

States are to be appointed in accordance with the

Clause.”). “Since the beginning of the nation,” Congress has addressed this problem through “vacancy

statutes” that grant the President the authority to

designate acting officials to “keep the federal bureaucracy humming.” SW General, Inc. v. National Labor

Relations Bd., 796 F.3d 67, 70 (D.C. Cir. 2015) (quotation marks omitted), aff’d, ––– U.S. ––––, 137 S.Ct.

929, 197 L.Ed.2d 263 (2017).

The Reform Act is the most recent iteration of that

interbranch accommodation. It provides for three options whenever a Senate-confirmed officer “dies, resigns, or is otherwise unable to perform the functions

and duties of the office[.]” 5 U.S.C. § 3345(a). The default is for the “first assistant” to take the helm. Id.

§ 3345(a)(1). But the Reform Act allows the President

to choose another person instead, as long as that person is either a Senate-confirmed appointee, id.

§ 3345(a)(2), or an employee within the same agency,

subject to certain duration-of-service and pay-scale

requirements, id. § 3345(a)(3). Mr. Whitaker was designated under the latter option, since his service as

chief of staff comported with the Reform Act’s duration-of-service and pay grade requirements. Guedes,

356 F.Supp.3d at 138 (“The parties do not dispute

that Whitaker satisfies the eligibility criteria in the

[Reform Act.]”).

Congress broadly designated the Reform Act to be

the “exclusive means for temporarily authorizing an

A14

acting official to perform the functions and duties of

any” Executive office that would otherwise require

Senate confirmation. 5 U.S.C. § 3347(a). But there is

an “unless”—Congress crafted exceptions to that exclusivity. Id. As relevant here, Section 3347(a) does

not control if another “statutory provision expressly

* * * designates an officer or employee to perform the

functions and duties of a specified office temporarily

in an acting capacity[.]” Id. § 3347(a)(1)(B).

The Attorney General Act, 28 U.S.C. § 508, is one

of those office-specific vacancy statutes. That statute

specifies a line of succession for a vacancy in the Office of the Attorney General. First in line is the Deputy Attorney General, who “may exercise all the duties

of th[e] office” and who, *12 “for the purpose of section 3345 of [the Reform Act],” is deemed “the first

assistant to the Attorney General.” 28 U.S.C.

§ 508(a). If the Deputy Attorney General is unavailable, the Attorney General Act directs that “the Associate Attorney General shall act as Attorney General,” and “[t]he Attorney General may designate the

Solicitor General and the Assistant Attorneys General, in further order of succession, to act as Attorney

General.” Id. § 508(b).

Codrea and the Department have battled at length

over the interaction between the Reform Act and the

Attorney General Act in the event of a vacancy in the

position of the Attorney General. The Government

maintains, and the district court agreed, that the two

statutes provide the President with alternative

means of designating an acting replacement. Guedes,

356 F.Supp.3d at 139; Gov’t Br. 40–58. Codrea, by

comparison, reads the Attorney General Act as the

A15

exclusive path for designating an acting Attorney

General, with the Reform Act available only after the

line of succession in the Attorney General Act has

been exhausted. Codrea Br. 20–21 (incorporating Coalition Br. 6). Codrea also argues that the designation

of a mere employee to perform the duties of a principal office like that of the Attorney General, even on

an acting basis, raises substantial constitutional

questions, at least when no exigency requires that

designation. Id. (adopting Coalition Reply Br. 15).

We need not wade into that thicket. While this appeal was pending, Attorney General Barr independently “familiarized [him]self with the rulemaking record [and] * * * reevaluated those materials

without any deference to [Whitaker’s] earlier decision.” 84 Fed. Reg. at 9,240. Following this “independent[ ] reevaluat[ion] [of] the * * * rule and the

underlying rulemaking record,” Attorney General

Barr “personally c[a]me to the conclusion that it

[wa]s appropriate to ratify and affirm the final rule.”

Id.

Codrea accepts the validity of Attorney General

Barr’s ratification as to both his statutory and his

Appointments Clause claims. Codrea Br. 20–21

(adopting Coalition Reply Br. 22); see also 5 U.S.C.

§ 3348(d)(1)–(2) (only prohibiting the ratification of

nondelegable duties); 28 U.S.C. § 510 (authorizing

delegation of “any function of the Attorney General”).

And with that act of ratification and the concession,

Codrea’s likelihood of success on the merits of his

challenge to the rule based on Acting Attorney General Whitaker’s role in its promulgation reduces to

zero.

A16

Codrea insists otherwise. He argues that Attorney

General Barr’s ratification does not moot the claim

because of the mootness doctrine’s exceptions for a

defendant’s voluntary cessation of challenged conduct

or for acts capable of repetition yet evading review.

Codrea Br. 20–21 (adopting Coalition Reply Br. 17).

That argument fails because ratification is generally

treated as a disposition on the legal merits of the appointments challenge and, in any event, no mootness

exception applies in this case.

1

The mootness doctrine “ensures compliance with

Article III’s case and controversy requirement by

‘limit[ing] federal courts to deciding actual, ongoing

controversies.’ ” Aref v. Lynch, 833 F.3d 242, 250

(D.C. Cir. 2016) (quoting American Bar Ass’n v. FTC,

636 F.3d 641, 645 (D.C. Cir. 2011) ). A case is moot if

our decision will neither “presently affect the parties’

rights nor have a more-than-speculative chance of affecting them in the future.” Id. (internal quotation

marks omitted) (quoting American Bar Ass’n, 636

F.3d at 645).

*13 We have repeatedly held that a properly appointed official’s ratification of an allegedly improper

official’s prior action, rather than mooting a claim,

resolves the claim on the merits by “remedy[ing] [the]

defect” (if any) from the initial appointment. WilkesBarre Hosp. Co. v. National Labor Relations Bd., 857

F.3d 364, 371 (D.C. Cir. 2017). This is so regardless of

whether “the previous [officer] was” or was not “validly appointed under either the Vacancies Act or the

Appointments Clause.” Intercollegiate Broad. Sys.

A17

Inc. v. Copyright Royalty Bd., 796 F.3d 111, 119 n.3

(D.C. Cir. 2015) (ratification defeats Appointments

Clause challenge) (citing Doolin Sec. Sav. Bank,

F.S.B. v. Office of Thrift Supervision, 139 F.3d 203,

205, 207, 212–214 (D.C. Cir. 1998), superseded by

statute on other grounds, Federal Vacancies Reform

Act of 1998, Pub. L. No. 105-277, 122 Stat. 2681, as

recognized in SW Gen., Inc., 796 F.3d at 70–71); FEC

v. Legi-Tech, Inc., 75 F.3d 704, 706, 708–710 (D.C.

Cir. 1996) (similar).

In Doolin, we treated the curative effects of ratification as analogous to rendering any defect in the

agency’s action “harmless error” under the Administrative Procedure Act, 5 U.S.C. § 706. 139 F.3d at

212. So viewed, ratification purges any residual taint

or prejudice left over from the allegedly invalid appointment. Legi-Tech, 75 F.3d at 708 n.5 (“[T]he issue

is not whether Legi-Tech was prejudiced by the original [decision], which it undoubtedly was, but whether, given the FEC’s remedial actions, there is sufficient remaining prejudice to warrant dismissal.”); Intercollegiate Broad., 796 F.3d at 124 (citing Legi-Tech

for the same proposition). When viewed as analogous

to harmless-error analysis, ratification is treated as

resolving the merits of the challenger’s claim in the

agency’s favor. Cf. Doolin, 139 F.3d at 212; Combat

Veterans for Cong. Political Action Comm. v. FEC,

795 F.3d 151, 157 (D.C. Cir. 2015) (rejecting a procedural challenge to a Federal Election Commission fine on the merits because the alleged infirmity produced no “prejudice”).

Those cases’ treatment of ratification as resolving

the merits of a claimed appointment flaw parallels

A18

how this court analyzes the agency practice of postpromulgation notice and comment. When an agency

“issues final regulations without the requisite comment period and then tries to cure that Administrative Procedure Act violation by holding a postpromulgation comment period,” we have repeatedly

held that the agency prevails on the merits as long as

it can demonstrate that it has kept an “open mind”

throughout the subsequent comment period. See, e.g.,

Intermountain Ins. Serv. of Vail v. Commissioner, 650

F.3d 691, 709 (D.C. Cir. 2011) (emphasis added), vacated and remanded on other grounds, 566 U.S. 972,

132 S.Ct. 2120, 182 L.Ed.2d 865 (2012), dismissed on

unopposed motion, No. 10-1204, 2012 WL 2371486, at

*1 (D.C. Cir. June 11, 2012); Advocates for Highway

& Auto Safety v. Federal Highway Admin., 28 F.3d

1288, 1291–1293 (D.C. Cir. 1994) (same).

Codrea points to Landry v. FDIC, 204 F.3d 1125

(D.C. Cir. 2000), in which this court resolved the merits of an Appointments Clause challenge to an administrative law judge’s decision, notwithstanding the

subsequent de novo review and affirmance of that decision by the agency itself, id. at 1131. That case is of

no help to Codrea. Landry carved out a narrow exception to ratification’s curative effect for Appointments

Clause challenges to the acts of “purely decision recommending employees.” Id. at 1131–1132. This court

explained that, if ratification were an escape hatch in

those cases, “then all such arrangements would escape judicial review” because the challenged ALJ action would never obtain judicial review without first

*14 exhausting that ratifying internal agency review

process. Id. Only when that particular “catch-22” is

A19

present does the Landry approach apply. Id.; accord

Intercollegiate Broad., 796 F.3d at 124 (distinguishing Landry on that basis). The succession of a Presidentially appointed and Senate-confirmed Attorney

General does not remotely implicate the Landry scenario.

2

Codrea argues that we should analyze the effect of

ratification through the lens of mootness rather than

treating ratification as resolving the case on the merits. Codrea Br. 20–21 (adopting Coalition Reply Br.

16–17).

Codrea notes that all of our prior ratification cases

dealt with appointments challenges that arose as defenses to enforcement actions that were being prosecuted by a properly appointed official, but that were

allegedly “tainted” by some preceding action of an unlawfully appointed official. Codrea Br. 20–21 (adopting Coalition Reply Br. 20); see, e.g., Intercollegiate

Broad., 796 F.3d at 124 (raising Appointments

Clause defense in a “subsequent proceeding” based on

the “continuing taint arising from the first” proceeding); Doolin, 139 F.3d at 212 (raising Appointments

Clause challenge to officer who issued the initial “Notice of Charges” to collaterally attack the ultimate

cease-and-desist order issued by a validly appointed

officer).

In that scenario, Codrea reasons, the appointment

issue arose only as an affirmative defense; no act intervened during litigation to eliminate the factual basis for an affirmative claim for relief in a way that

generally would trigger mootness analysis. Here, by

A20

contrast, Codrea has raised as a plaintiff an independent, pre-enforcement challenge to an agency rule

in an attempt to avert a present duty to comply, and

he filed suit at a time when the allegedly improperly

appointed official was still in office and enforcing his

own challenged decision. For that reason, the effect of

Attorney General Barr’s intervening ratification

must be guided not by a merits analysis, but rather

by mootness. Codrea Br. 20–21 (adopting Coalition

Reply Br. 17); see, e.g., EEOC v. First Citizens Bank

of Billings, 758 F.2d 397, 399–400 (9th Cir. 1985)

(treating congressional ratification as causing mootness); see also Thomas v. Network Solutions, Inc., 176

F.3d 500, 506 (D.C. Cir. 1999) (assuming that congressional ratification mooted an unauthorized-tax

claim).

The problem for Codrea is that, even if we were to

adopt his proposed analytical approach, his claim still

lacks any discernible likelihood of success on the merits because no exception to mootness fits this scenario.

First, this case does not implicate the exception to

mootness for cases that are “capable of repetition, yet

evading review.” United States v. Sanchez-Gomez, ––

– U.S. ––––, 138 S.Ct. 1532, 1540, 200 L.Ed.2d 792

(2018). For a controversy to be “capable of repetition,”

Codrea bears the burden of showing that (i) the challenged action is “in its duration too short to be fully

litigated prior to its cessation or expiration,” and (ii)

there is a “reasonable expectation that the same

complaining party will be subject to the same action

again.” Davis v. FEC, 554 U.S. 724, 735, 128 S.Ct.

2759, 171 L.Ed.2d 737 (2008) (citations omitted);

A21

Honeywell Int’l, Inc. v. Nuclear Regulatory Comm’n,

628 F.3d 568, 576 (D.C. Cir. 2010) (party asserting

capable of repetition bears burden of proof) (citing

Southern Co. Servs., Inc. v. FERC, 416 F.3d 39, 43

(D.C. Cir. 2005) ). Under that test, “[t]he ‘wrong’ that

is, or is not, ‘capable of repetition’ must be defined in

terms of the precise controversy it spawns.” *15 People for Ethical Treatment of Animals, Inc. v. Gittens,

396 F.3d 416, 422 (D.C. Cir. 2005) (emphasis added).

This demand for particularity ensures “that courts

resolve only continuing controversies between the

parties.” Id.

Here, Codrea has wholly failed to show that appointments claims like his are too short-fused to obtain judicial resolution, or that there is anything

more than the most remote and “theoretical[ ] possib[ility]” of repetition, Nelson v. Miller, 570 F.3d 868,

882 (7th Cir. 2009). For Codrea’s legal injury to recur,

(i) the Attorney General would have to leave office;

(ii) the President would then have to appoint a mere

employee in his stead (something Codrea argues has

not happened more than a “handful” of times in history (Codrea Br. 20–21 (adopting Coalition Br. 38;

Coalition Reply Br. 15–16)); (iii) that the new Acting

Attorney General would then have to promulgate a

legislative rule; and (iv) by sheer coincidence, that

rule would have to adversely affect Codrea or his coplaintiffs’ legal rights. It takes more than such quixotic speculation to save a case from mootness, even

when the Executive continues to defend its prerogatives in litigation. See Larsen v. United States Navy,

525 F.3d 1, 4 (D.C. Cir. 2008).

A22

Second, Codrea’s invocation of the rule that a defendant’s voluntary cessation of challenged activity

will not moot a case fares no better. See Friends of the

Earth, Inc. v. Laidlaw Environmental Servs., 528

U.S. 167, 189, 120 S.Ct. 693, 145 L.Ed.2d 610 (2000).

The voluntary-cessation rule is designed to deter the

wrongdoer who would otherwise “engage in unlawful

conduct, stop when sued to have the case declared

moot, then pick up where he left off, repeating this

cycle until he achieves all his unlawful ends.” Already, LLC v. Nike, Inc., 568 U.S. 85, 91, 133 S.Ct.

721, 184 L.Ed.2d 553 (2013). For that reason, a party’s voluntary cessation of challenged conduct will not

moot a case unless it is “absolutely clear that the allegedly wrongful behavior could not reasonably be

expected to recur.” Laidlaw Environmental Servs.,

528 U.S. at 189, 120 S.Ct. 693 (internal quotation

marks omitted).2

The voluntary-cessation doctrine has no apparent

relevance here. That is because the power to effect

the legally relevant ratification by a duly installed

Attorney General—the supposed source of “cessation”—lies beyond the unilateral legal authority of

any of the named defendants, the Office of the Attor2 It bears noting that the merits-based analysis of prejudice

that Codrea seeks to avoid includes a somewhat analogous exception for a defendant’s strategic manipulation of the process to

avoid judicial review. See Sugar Cane Growers Co-op. of Fla. v.

Veneman, 289 F.3d 89, 96 (D.C. Cir. 2002) (“[I]f the government

could skip [the APA’s rulemaking] procedures, engage in informal consultation, and then be protected from judicial review unless a petitioner could show a new argument—not [already] presented informally,” then the APA’s prescribed rulemaking process “obviously would be eviscerated.”).

A23

ney General, or even the President of the United

States. Under the peculiar circumstances of this case,

where the ratification was a result of the combined

actions of a presidential nomination and an independent Senate confirmation, the “voluntariness” in

“voluntary cessation” is not implicated.

Aimed as it is at party manipulation of the judicial

process through the false pretense of singlehandedly

ending a dispute, the voluntary-cessation exception

presupposes that the infringing party voluntarily exercises its own unilateral power not only to terminate

the suit and evade judicial review, but also to “pick

up where he left off” and complete the devious “cycle”

after the litigation is dismissed. Already, LLC, 568

U.S. at 91, 133 S.Ct. 721; *16 see City News & Novelty, Inc. v. City of Waukesha, 531 U.S. 278, 284 n.1,

121 S.Ct. 743, 148 L.Ed.2d 757 (2001) (explaining

that the “rule traces to the principle that a party

should not be able to evade judicial review, or to defeat a judgment, by temporarily altering questionable

behavior”) (emphasis added); Knox v. Service Emps.

Int’l Union, 567 U.S. 298, 307, 132 S.Ct. 2277, 183

L.Ed.2d 281 (2012) (voluntary cessation concerns a

defendant’s “resumption of * * * challenged conduct

as soon as the case is dismissed”) (emphasis added);

United States v. W.T. Grant Co., 345 U.S. 629, 632,

73 S.Ct. 894, 97 L.Ed. 1303 (1953) (voluntarycessation doctrine rooted in concern over leaving a

“defendant * * * free to return to his old ways”).

That framework ill fits a situation where, as here,

the intervening acts of independent third parties are

essential to accomplish a legally relevant change in

circumstances. Here, ratification materially changed

A24

the circumstances of the litigation only because it

was undertaken by a validly appointed Attorney

General whose authority to act Codrea does not challenge. Codrea Br. 20–21 (adopting Coalition Reply

Br. 22) (“Plaintiff assumes that the ratification was

not tainted by Mr. Whitaker’s actions in promulgating the Rule in the first place.”). That “cessation” of

the legal challenge was outside the hands of the

named defendants—then-Acting Attorney General

Whitaker, the Bureau of Alcohol, Tobacco, Firearms

and Explosives, Acting Bureau Director Thomas

Brandon, and Attorney General William Barr. The

essential predicate for that legally relevant form of

cessation was the (non-defendant) President’s nomination and the (non-defendant) Senate’s independent

confirmation of a new Attorney General, and their

endowment of him with the authority to “cease” the

litigation by way of ratification.

In other words, the defendants in this case lacked

the unilateral power, or the power at all, to voluntarily cease and restart the conduct complained of—

having a Reform-Act-appointed Acting Attorney General promulgate or enforce a rule adversely affecting

Guedes and Codrea. Without such power, the risk of

manipulating the litigation process evaporates. In

addition, the deliberative burdens of the Senate’s intervening and independent advice-and-consent role

extinguish the strategic concerns animating the voluntary-cessation doctrine in the first place. Cf. Clarke

v. United States, 915 F.2d 699, 705 (D.C. Cir. 1990)

(en banc) (raising “serious doubts” about “applying

the doctrine to Congress” because, “in the absence of

overwhelming evidence (and perhaps not then), it

A25

would seem inappropriate for the courts either to impute such manipulative conduct to a coordinate

branch of government, or to apply against that

branch a doctrine that appears to rest on the likelihood of a manipulative purpose”); United States Dep’t

of the Treasury v. Galioto, 477 U.S. 556, 560, 106

S.Ct. 2683, 91 L.Ed.2d 459 (1986) (analyzing the

mooting effects of Congressional amendment without

reference to voluntary cessation). At the very least,

Codrea has a vanishingly low likelihood of prevailing

on that theory.3

*17 In sum, because Codrea has shown no likelihood of success on his appointment-based challenges

due to Attorney General Barr’s independent and unchallenged ratification of the Bump-Stock Rule, the

district court did not abuse its discretion in denying a

preliminary injunction based on those statutory and

constitutional claims.

3 This case does not present, and we need not decide, whether

the President’s unilateral designation of a different acting Attorney General would have implicated the voluntary-cessation

doctrine. See Trinity Lutheran Church of Columbia, Inc. v. Comer, ––– U.S. ––––, 137 S.Ct. 2012, 2019 n.1, 198 L.Ed.2d 551

(2017) (no mootness when Governor ordered state Department

of Natural Resources to rescind challenged policy, where there

was no evidence the Department “could not revert to its policy of

excluding religious organizations”); cf. Doe v. Harris, 696 F.2d

109, 113 (D.C. Cir. 1982) (applying the capable of repetition doctrine to “different official actors” within the same U.S. Attorney’s Office). What matters in this case is not that the BumpStock Rule was ratified by someone other than Acting Attorney

General Whitaker, but that it was ratified by someone whose

authority to undertake such a ratification—by virtue of Presidential nomination and Senate confirmation—Codrea admits he

cannot challenge.

A26

B

We next consider the plaintiffs’ contention that the

Bureau lacked statutory authority to promulgate the

Bump-Stock Rule. Specifically, Guedes and Codrea

argue that the statutory definition of “machinegun”

cannot be read to include bumpstock devices. Guedes

and Codrea have not demonstrated a substantial

likelihood of success on that claim.

1

At the outset, we must determine the standard by

which to assess the Rule’s conclusion that bumpstock devices amount to “machineguns” under the

statutory definition. In particular, should we examine

the Rule’s conclusion to that effect under the Chevron

framework, or is Chevron inapplicable?

If Chevron treatment is in order, we first ask if the

statute is ambiguous concerning whether bump-stock

devices can be considered “machineguns”; and if so,

we sustain the Rule’s conclusion that bump-stock devices are machine guns as long as it is reasonable.

See, e.g., Entergy Corp. v. Riverkeeper, Inc., 556 U.S.

208, 218, 129 S.Ct. 1498, 173 L.Ed.2d 369 (2009).

Crucially, at this second step under Chevron, an

“agency need not adopt * * * the best reading of the

statute, but merely one that is permissible.” Dada v.

Mukasey, 554 U.S. 1, 29 n.1, 128 S.Ct. 2307, 171

L.Ed.2d 178 (2008). Conversely, if Chevron’s two-step

framework is inapplicable, we accept the agency’s interpretation only if it is the best reading of the statute.

Much, then, can turn on whether an agency’s interpretation merits treatment under Chevron. For

A27

that reason, and because none of the parties presents

an argument for applying the Chevron framework

(the plaintiffs contend that Chevron is inapplicable

and the government does not argue otherwise), we

devote considerable attention to the question of Chevron’s applicability to the Bump-Stock Rule. We conclude that the Rule warrants consideration under

Chevron.

a

The applicability of Chevron materially depends on

what kind of rule the Bump-Stock Rule represents.

There is a “central distinction” under the Administrative Procedure Act between legislative rules and interpretive rules. Chrysler Corp v. Brown, 441 U.S.

281, 301, 99 S.Ct. 1705, 60 L.Ed.2d 208 (1979); see 5

U.S.C. § 553(b), (d). And that distinction centrally informs the applicability of Chevron. “Legislative rules

generally receive Chevron deference,” Nat’l Mining

Ass’n v. McCarthy, 758 F.3d 243, 251 (D.C. Cir.

2014), whereas “interpretive rules * * * enjoy no

Chevron status as a class,” United States v. Mead

Corp., 533 U.S. 218, 232, 121 S.Ct. 2164, 150 L.Ed.2d

292 (2001); see also Nat’l Mining Ass’n, 758 F.3d at

251 (observing that interpretive rules “often do not”

receive Chevron deference).

Legislative rules result from an agency’s exercise

of “delegated legislative *18 power” from Congress.

Am. Mining Cong. v. Mine Safety & Health Admin.,

995 F.2d 1106, 1109 (D.C. Cir. 1993). Accordingly,

legislative rules have the “force and effect of law.”

Encino Motorcars, LLC v. Navarro, ––– U.S. ––––,

136 S.Ct. 2117, 2122, 195 L.Ed.2d 382 (2016). Inter-

A28

pretive rules, on the other hand, are “issued by an

agency to advise the public of the agency’s construction of the statutes and rules which it administers.”

Shalala v. Guernsey Mem’l Hosp., 514 U.S. 87, 99,

115 S.Ct. 1232, 131 L.Ed.2d 106 (1995). Because they

are not an exercise of delegated legislative authority,

interpretive rules “do not have the force and effect of

law and are not accorded that weight in the adjudicatory process.” Id. While legislative rules generally require notice and comment, interpretive rules need

not issue pursuant to any formalized procedures. See

5 U.S.C. § 553(b).

To determine whether a rule is legislative or interpretive, we ask whether the agency “intended” to

speak with the force of law. Encino Motorcars, 136

S.Ct. at 2122; Am. Mining Cong., 995 F.2d at 1109.

Central to the analysis is the “language actually used

by the agency.” Cmty. Nutrition Inst. v. Young, 818

F.2d 943, 946 (D.C. Cir. 1987) (per curiam). We also

consider “whether the agency has published the rule

in the Code of Federal Regulations” and “whether the

agency has explicitly invoked its general legislative

authority.” Am. Mining Cong., 995 F.2d at 1112.

All pertinent indicia of agency intent confirm that

the Bump-Stock Rule is a legislative rule. The Rule

unequivocally bespeaks an effort by the Bureau to adjust the legal rights and obligations of bump-stock

owners—i.e., to act with the force of law. The Rule

makes clear throughout that possession of bumpstock devices will become unlawful only as of the

Rule’s effective date, not before.

A29

To that end, the Rule informs bump-stock owners

that their devices “will be prohibited when this rule

becomes effective.” 83 Fed. Reg. at 66,514 (emphasis

added). It correspondingly assures bump-stock owners that “[a]nyone currently in possession of a bumpstock-type device is not acting unlawfully unless they

fail to relinquish or destroy their device after the effective date of this regulation.” Id. at 66,523 (emphasis added). And the Rule “provides specific information about acceptable methods of disposal, as well

as the timeframe under which disposal must be accomplished to avoid violating 18 U.S.C. § 922(o).” Id.

at 66,530 (emphasis added). Reinforcing the point,

the Rule says it will “criminalize only future conduct,

not past possession of bumpstock-type devices that

ceases by the effective date.” Id. at 66,525 (emphasis

added).

Those statements, and others like them in the

Rule, embody an effort to “directly govern[ ] the conduct of members of the public, affecting individual

rights and obligations.” Long Island Care at Home,

Ltd. v. Coke, 551 U.S. 158, 172, 127 S.Ct. 2339, 168

L.Ed.2d 54 (2007) (internal quotation marks omitted). That is powerful evidence that the Bureau “intended [the Rule] as a binding application of its

rulemaking authority.” Id.

The Bureau further evinced its intent to exercise

legislative authority by expressly invoking the Chevron framework and then elaborating at length as to

how Chevron applies to the Rule. The Rule observes

that, “[w]hen a court is called upon to review an

agency’s construction of the statute it administers,

the court looks to the framework set forth in Chevron

A30

U.S.A., Inc. v. Natural Resources Defense Council,

Inc.” 83 Fed. Reg. at 66,527. The Rule then contains

several paragraphs of *19 analysis describing the application of each of Chevron’s two steps to the Rule.

That discussion is compelling evidence that the Bureau did not conceive of its rule as merely interpretive. Because “interpretive rules * * * enjoy no Chevron status as a class,” Mead, 533 U.S. at 232, 121

S.Ct. 2164, the Bureau’s exegesis on Chevron would

have served no purpose unless the agency intended

the Rule to be legislative in character.

Other evidence of agency intent points to the same

conclusion. One consideration under our decisions is

“whether the agency has explicitly invoked its general legislative authority.” Am. Mining Cong., 995

F.2d at 1112. The Rule does exactly that, invoking

two separate delegations of legislative authority. See

83 Fed. Reg. at 66,515. The first is 18 U.S.C. § 926(a),

which empowers the Attorney General to “prescribe

only such rules and regulations as are necessary to

carry out the provisions of [the Gun Control Act].”

The second is 26 U.S.C. § 7805(a), which grants the

Attorney General authority to “prescribe all needful

rules and regulations” for the enforcement of the National Firearms Act. See 26 U.S.C. § 7801(a)(2)(A).

Both of those provisions, the Rule states, vest “the responsibility for administering and enforcing the NFA

and GCA” in the Attorney General. 83 Fed. Reg. at

66,515.

The Rule’s publication in the Code of Federal Regulations also indicates that it is a legislative rule. See

Am. Mining Cong., 995 F.2d at 1112. By statute, publication in the Code of Federal Regulations is limited

A31

to rules “having general applicability and legal effect.” 44 U.S.C. § 1510 (emphasis added). The BumpStock Rule amends three sections of the Code, modifying the regulatory definition of “machine gun” and

“adding a sentence to clarify that a ‘machine gun’ includes * * * a bump-stock-type device.” 83 Fed. Reg.

at 66,519 (amending 27 C.F.R. §§ 447.11, 478.11,

479.11). Those sorts of amendments would be highly

unusual for a mere interpretive rule.

In short, the Rule confirms throughout, in numerous ways, that it intends to speak with the force of

law. It contained all of those indicia uniformly conveying its intended legislative character when Acting

Attorney General Whitaker issued it. And it still contained those indicia when Attorney General Barr

subsequently ratified it.

Notwithstanding all of that, the government’s litigating position in this case seeks to reimagine the

Rule as merely interpretive. The government’s briefing says that the Rule is “not an act of legislative

rulemaking,” and that the Rule instead only “sets

forth the agency’s interpretation of the best reading

of the statutory definition of ‘machinegun.’ ” Gov’t Br.

38.

The government’s position to that effect has highly

significant implications for owners of bump-stock devices. Whereas a legislative rule, as an exercise of

delegated lawmaking authority, can establish a new

legal rule going forward, an interpretive rule by nature simply communicates the agency’s interpretation of what a statute has always meant. So here, if

the Bump-Stock Rule is merely interpretive, it con-

A32

veys the government’s understanding that bumpstock devices have always been machine guns under

the statute. The government says exactly that in its

brief, observing that, per the interpretation set out in

the Rule, “any bump stock made after 1986 has always been a machinegun.” Gov’t Br. 38.

That in turn would mean that bump-stock owners

have been committing a felony for the entire time

they have possessed the devices. Under 18 U.S.C. §

922(o)(1), it is “unlawful for any person to transfer or

possess a machinegun,” and violators “shall be fined

[or] imprisoned not more *20 than 10 years, or both,”

id. § 924(a)(2). As the government acknowledges, under the view it espouses in its brief that the Rule is

interpretive, the possession of bump stocks “has always been banned.” Gov’t Br. 38. And that would be

so notwithstanding a number of prior contrary interpretations by the agency. See 83 Fed. Reg. at 13,444–

13,446.

The government’s account of the Rule in its brief—

including its position that bump-stock owners have

always been felons—is incompatible with the Rule’s

terms. The Rule gives no indication that bump stocks

have always been machine guns or that bump-stock

owners have been committing a felony for the entire

time they have possessed the device. The Rule in fact

says the opposite. After all, it establishes an effective

date, after which (and only after which) bump-stock

possession will be prohibited. 83 Fed. Reg. at 66,523.

A future effective date of that kind cannot be reconciled with a supposed intent to convey that bumpstock possession “has always been banned.” Gov’t Br.

38.

A33

The government now characterizes the Rule’s effective date as merely marking the end of a period of

discretionary withholding of enforcement, in that the

Rule informs the public that the Department will

“not pursue enforcement action against individuals

who sold or possessed bump stocks prior to the effective date.” Id. at 38–39. Once again, that is not what

the Rule says. The government engages in enforcement discretion when it voluntarily refrains from

prosecuting a person even though he is acting unlawfully. The Rule, by contrast, announces that a person

“in possession of a bumpstock type device is not acting unlawfully unless they fail to relinquish or destroy their device after the effective date of this regulation.” 83 Fed. Reg. at 66,523 (emphases added).

That is the language of a legislative rule establishing

when bump-stock possession will become unlawful,

not an interpretive rule indicating it has always been

unlawful.

In short, the government cannot now, in litigation,

reconceive the Bump-Stock Rule as an interpretive

rule. The character of a rule depends on the agency’s

intent when issuing it, not on counsel’s description of

the rule during subsequent litigation. See Encino Motorcars, 136 S.Ct. at 2122; cf. SEC v. Chenery Corp.,

318 U.S. 80, 87–88, 63 S.Ct. 454, 87 L.Ed. 626 (1943).

Here, that intent is unmistakable: the Bump-Stock

rule is a legislative rule.

b

Ordinarily, legislative rules receive Chevron deference. See Nat’l Mining Ass’n, 758 F.3d at 251. This

legislative rule is no different.

A34

The Supreme Court has established that we afford

Chevron deference if we determine (i) “that Congress

delegated authority to the agency generally to make

rules carrying the force of law,” and (ii) “that the

agency interpretation claiming deference was promulgated in the exercise of that authority.” Mead, 533

U.S. at 226–227, 121 S.Ct. 2164 (2001). Here, both

are true.

First, we know Congress intended a delegation of

legislative authority to the agency because Congress

made the relevant delegations express. As noted, the

Attorney General has the power to prescribe “such

rules and regulations as are necessary to carry out

the provisions of” the Gun Control Act. 18 U.S.C. §

926(a). And the Attorney General “shall prescribe all

needful rules and regulations for the enforcement of”

the National Firearms Act. 26 U.S.C. § 7805(a); see

id. § 7801(a)(2)(A). “[A] general conferral of rulemaking authority” of that variety “validate[s] rules for all

the matters the agency *21 is charged with administering.” City of Arlington v. FCC, 569 U.S. 290, 306,

133 S.Ct. 1863, 185 L.Ed.2d 941 (2013). The Supreme

Court has said exactly that for § 7805(a), one of the

delegations of authority at issue. Specifically discussing that very provision, the Court explained that it

has “found such ‘express congressional authorizations

to engage in the process of rulemaking’ to be ‘a very

good indicator of delegation meriting Chevron treatment.’ ” Mayo Found. for Med. Educ. & Research v.

United States, 562 U.S. 44, 57, 131 S.Ct. 704, 178

L.Ed.2d 588 (2011) (quoting Mead, 533 U.S. at 229,

121 S.Ct. 2164).

A35

Second, we know that the Bureau promulgated the

Bump-Stock Rule “in the exercise of that authority”

to “make rules carrying the force of law” because that

criterion is the defining characteristic of a legislative

rule. Mead, 533 U.S. at 227, 121 S.Ct. 2164. And we

have already determined that the Rule is legislative

in character. We are then firmly within Chevron’s

domain.

Nonetheless, the parties protest the applicability

of Chevron on several grounds. The plaintiffs first argue that Chevron deference has been waived or forfeited by the government. Next, the parties (including

the government) submit that Chevron deference is

inapplicable in the context of criminal statutes. And

finally, Guedes contends that Chevron deference for

criminal statutes is displaced by the rule of lenity.

None of those objections to applying Chevron, we conclude, is likely to succeed in the context of the BumpStock Rule.

(i)

The agency plainly believed it was acting in a

manner warranting Chevron treatment given that it

expressly invoked the Chevron framework in the

Rule. The plaintiffs assert that the government nonetheless has forfeited, or even waived, the application

of Chevron deference by declining to argue for it in

this litigation. And while the government has not

taken a definitive position before us on whether

Chevron can be waived or forfeited, it has declined to

invoke Chevron throughout the course of the litigation.

A36

In particular, in its briefing before the district

court, the government expressly disclaimed any entitlement to Chevron deference. And after the district

court nonetheless relied on Chevron to affirm the

Rule, the government filed notices in other pending

challenges to the Rule, stating that it “ha[s] not contended that the deference afforded under Chevron * *

* applies in this action.’” E.g., Notice of Supplemental

Authority at 2, Gun Owners of Am., Inc. v. Barr, No.

1:18-cv-1429 (W.D. Mich. Feb. 27, 2019), ECF No. 38.

Now, in this appeal, the government affirmatively

disclaims any reliance on Chevron. See Gov’t Br. 37.

And at oral argument, the government went so far as

to indicate that, while it believes the Rule should be

upheld as the best reading of the statute without any

need for Chevron deference, if the Rule’s validity

turns on the applicability of Chevron, it would prefer

that the Rule be set aside rather than upheld under

Chevron. Oral Argument at 42:38–43:45.

To the extent Chevron treatment can be waived,

we assume that the government’s posture in this litigation would amount to a waiver rather than only a

forfeiture. See Wood v. Milyard, 566 U.S. 463, 470

n.4, 132 S.Ct. 1826, 182 L.Ed.2d 733 (2012) (“A

waived claim or defense is one that a party has knowingly and intelligently relinquished; a forfeited plea

is one that a party has merely failed to preserve.”).

But our court has yet to address whether, when an

agency promulgates a rule that would otherwise

plainly occasion the application of Chevron, agency

counsel could nonetheless opt to effect a waiver of

Chevron treatment *22 when later defending against

a challenge to the rule.

A37

We have, however, held that an agency’s lawyers

cannot forfeit the applicability of Chevron deference

unless the underlying agency action fails to “manifests its engagement in the kind of interpretive exercise to which review under Chevron generally applies—i.e., interpreting a statute it is charged with

administering in a manner (and through a process)

evincing an exercise of its lawmaking authority.”

SoundExchange, Inc. v. Copyright Royalty Bd., 904

F.3d 41, 54 (D.C. Cir. 2018). We grounded our holding in the principle that “it is the expertise of the

agency, not its lawyers,” that underpins Chevron. Id.

(quoting Peter Pan Bus Lines, Inc. v. Fed. Motor Carrier Safety Admin., 471 F.3d 1350, 1354 n.3 (D.C. Cir.

2006)); see also Chenery, 318 U.S. at 87–88, 63 S.Ct.

454. We see no reason that the same limitations on

forfeiture of Chevron should not also govern waiver of

Chevron.

Forfeiture and waiver involve, respectively, a failure to invoke, or an affirmative decision not to invoke, a party’s “right or privilege.” Johnson v. Zerbst,

304 U.S. 458, 464, 58 S.Ct. 1019, 82 L.Ed. 1461

(1938). But Chevron is not a “right” or “privilege” belonging to a litigant. It is instead a doctrine about

statutory meaning—specifically, about how courts

should construe a statute.

If a statute contains ambiguity, Chevron directs

courts to construe the ambiguity as “an implicit delegation from Congress to the agency to fill in the statutory gaps.” FDA v. Brown & Williamson Tobacco

Corp., 529 U.S. 120, 159, 120 S.Ct. 1291, 146 L.Ed.2d

121 (2000). If there is ambiguity, the meaning of the

statute becomes whatever the agency decides to fill

A38

the gaps with, as long as the agency’s interpretation

is reasonable and “speak[s] with the force of law.”

Mead, 533 U.S. at 229, 121 S.Ct. 2164. And insofar as

Chevron concerns the meaning of a statute, it is an

awkward conceptual fit for the doctrines of forfeiture

and waiver.

We, for example, would give no mind to a litigant’s

failure to invoke interpretive canons such as expressio unius or constitutional avoidance even if she intentionally left them out of her brief. “[T]he court is

not limited to the particular legal theories advanced

by the parties, but rather retains the independent

power to identify and apply the proper construction of

governing law.” Kamen v. Kemper Fin. Servs., Inc.,

500 U.S. 90, 99, 111 S.Ct. 1711, 114 L.Ed.2d 152

(1991). The “independent power” to identify and apply the correct law presumably includes application

of the Chevron framework when determining the

meaning of a statute.

Allowing an agency to freely waive Chevron treatment in litigation also would stand considerably in

tension with basic precepts of administrative law. As

we have explained, a legislative rule qualifying for

Chevron deference remains legislative in character

even if the agency claims during litigation that the

rule is interpretive: Chenery instructs that the proper

subject of our review is what the agency actually did,

not what the agency’s lawyers later say the agency

did. See 318 U.S. at 87–88, 63 S.Ct. 454. Accordingly,

we have held that a particular rule is legislative rather than interpretive over the protestations of the

agency. See, e.g., Cmty. Nutrition Inst., 818 F.2d at

946. And once we conclude that a rule is legislative, it

A39

follows that we generally review the rule’s validity

under the Chevron framework. See Nat’l Mining

Ass’n, 758 F.3d at 251.

A waiver regime, moreover, would allow an agency

to vary the binding nature of a legislative rule merely

by asserting in litigation that the rule does not carry

the *23 force of law, even though the rule speaks to

the public with all the indicia of a legislative rule.

Agency litigants then could effectively amend or

withdraw the legal force of a rule without undergoing

a new notice-and-comment rulemaking. That result

would enable agencies to circumvent the Administrative Procedure Act’s requirement “that agencies use

the same procedures when they amend or repeal a

rule as they used to issue the rule in the first instance.” Perez v. Mortg. Bankers Ass’n, ––– U.S. ––––,

135 S.Ct. 1199, 1206, 191 L.Ed.2d 186 (2015). And an

agency could attempt to secure rescission of a policy

it no longer favors without complying with the Administrative Procedure Act, or perhaps could avoid

the political accountability that would attend its own

policy reversal by effectively inviting the courts to set

aside the rule instead.

We

thus

conclude,

consistent

with

SoundExchange’s approach to forfeiture of Chevron,

that an agency’s lawyers similarly cannot waive

Chevron if the underlying agency action “manifests

its engagement in the kind of interpretive exercise to

which review under Chevron generally applies.”

SoundExchange, 904 F.3d at 54. In that event, we

“apply Chevron * * * even if there is no invocation of

Chevron in the briefing in our court.” Id.

A40

In this case, the Bump-Stock Rule plainly indicates the agency’s view that it was engaging in a

rulemaking entitled to Chevron deference. That observation naturally follows from the Rule’s legislative

character, which generally yields treatment under

Chevron. See Nat’l Mining Ass’n, 758 F.3d at 251.

And for this Rule in particular, another telltale sign

of the agency’s belief that it was promulgating a rule

entitled to Chevron deference is the Rule’s invocation

of Chevron by name. To be sure, an agency of course

need not expressly invoke the Chevron framework to

obtain Chevron deference: “Chevron is a standard of

judicial

review,

not

of

agency

action.”

SoundExchange, 904 F.3d at 54. Still, the Bureau’s

invocation of Chevron here is powerful evidence of its

intent to engage in an exercise of interpretive authority warranting Chevron treatment.

The Bureau, in rejecting objections that the agency’s interpretation “would not be entitled to deference

under Chevron,” 83 Fed. Reg. at 66,526, specifically

invoked the Chevron framework and marched

through its two-step analysis, id. at 66,527. At step

one, the agency explained that its interpretation “accord[ed] with the plain meaning” of the statute. And

at step two, the agency explained that it “ha[d] the

authority to interpret elements of the definition of

‘machinegun’ like ‘automatically’ and ‘single function

of the trigger,’ ” concluding that its “construction of

those terms is reasonable under Chevron [Step Two].”

Id.

The Rule expressly defends the agency’s reading of

the statute as an interpretive exercise implicating

Chevron. Agency counsel’s later litigating decision to

A41

refrain from invoking Chevron thus affords no basis

for our denying the Rule Chevron status.

(ii)

Next, the plaintiffs submit that Chevron deference

has no application to regulations interpreting statutes like the National Firearms Act and the Gun

Control Act because they impose criminal penalties

on violators. Chevron deference in the context of such

statutes, the plaintiffs urge, would flout an understanding that “criminal laws are for courts, not for

the Government, to construe.” Abramski v. United

States, 573 U.S. 169, 191, 134 S.Ct. 2259, 189

L.Ed.2d 262 (2014). And the plaintiffs are not the only parties who question Chevron’s salience in the

criminal context. The government’s *24 decision to

refrain from invoking Chevron in this litigation appears to stem from the same concerns. See Gov’t Br.

36–37.

Guedes and Codrea, however, have failed to

demonstrate a likelihood of success in establishing a

general rule against applying Chevron to agency interpretations of statutes that have criminal-law implications. To the contrary, precedent says otherwise.

Start with Chevron itself. At issue in Chevron was

the meaning of the term “stationary source” in the

Clean Air Act. See Chevron, 467 U.S. at 840, 104

S.Ct. 2778. The scope of that term defined the statutory obligation of private parties, under state implementation plans, to obtain permits for the construction and operation of “new or modified major stationary sources of air pollution.” 42 U.S.C. § 7502(a)(1),

(b)(6) (1982). But at the time, any person who know-

A42

ingly violated any requirement of a state implementation plan (after notice from the EPA) faced a fine of

$25,000 a day or imprisonment for up to a year, or

both. See id. § 7413(c)(1) (1982). Nevertheless, the

Chevron Court established the decision’s namesake

deference.

For another example, consider the securities laws.

The SEC’s interpretation of those laws regularly receives Chevron treatment, e.g., Nat’l Ass’n of Mfrs. v.

SEC, 748 F.3d 359, 366 (D.C. Cir. 2014); Am. Equity

Inv. Life Ins. Co. v. SEC, 613 F.3d 166, 172–173 (D.C.

Cir. 2010); Markowski v. SEC, 274 F.3d 525, 528–529

(D.C. Cir. 2001), even though their violation often

triggers criminal liability. The Securities Exchange

Act, for instance, imposes criminal sanctions for willful violations of “any provision” of the Act or “any

rule or regulation thereunder the violation of which

is made unlawful.” 15 U.S.C. § 78ff(a). Yet in United

States v. O’Hagan—a criminal case—the Supreme

Court accorded Chevron deference to an SEC rule

that interpreted a provision of the Act in a manner

rendering the defendant’s conduct a crime. 521 U.S.

642, 667, 673, 117 S.Ct. 2199, 138 L.Ed.2d 724 (1997)

(citing Chevron, 467 U.S. at 844, 104 S.Ct. 2778). The

Court noted that Congress had authorized the Commission “to prescribe legislative rules,” and held that

the rule in question, issued in an exercise of that authority, should receive “controlling weight” under

Chevron. Id. at 673, 117 S.Ct. 2199 (quoting Chevron,

467 U.S. at 844, 104 S.Ct. 2778).

While the Court in O’Hagan applied Chevron in a

criminal case, it (like Chevron itself) did not specifically address whether the criminal context should

A43

have afforded a basis for denying deference to the

agency’s interpretation. But the Court engaged with

that precise issue in Babbitt v. Sweet Home Chapter

of Communities for a Great Oregon, 515 U.S. 687, 115

S.Ct. 2407, 132 L.Ed.2d 597 (1995). There, the Court

reviewed a regulation interpreting the term “take” in

the Endangered Species Act. The challengers argued

that Chevron deference was inappropriate because

the Endangered Species Act included criminal penalties for certain violations. See id. at 704 n.18, 115

S.Ct. 2407. The Court disagreed, holding that, notwithstanding the statute’s criminal penalties, it

would defer “to the Secretary’s reasonable interpretation” under Chevron. See id. at 703–704 & 704, 115

S.Ct. 2407 n.18.

Our circuit precedent is in accord. Recently, in

Competitive Enterprise Institute v. United States Department of Transportation, 863 F.3d 911 (D.C. Cir.

2017), we explained that “[w]e apply the Chevron

framework * * * even though violating [the statute]

can bring criminal penalties,” id. at 915 n.4 (citing

Babbitt, 515 U.S. at 704 n.18, 115 S.Ct. 2407); see id.

at 921 (Kavanaugh, J., concurring) (“I join the *25

majority opinion[.]”). That precedent is controlling

here. See also Humane Society v. Zinke, 865 F.3d 585,

591, 595 (D.C. Cir. 2017) (applying Chevron even

though the challenged rule interpreted the Endangered Species Act, the violation of which results in

“criminal sanctions”).

Also, at least twice before, we afforded Chevron

deference to an agency’s construction of a statute in

the criminal context over the express objection of a

defendant. In United States v. Kanchanalak, 192

A44

F.3d 1037 (D.C. Cir. 1999), the defendants “argue[d]

that this court should not give Chevron deference to

the FEC’s interpretation of an ambiguous statute in a

criminal proceeding,” id. at 1047 n.17. We disagreed:

“That criminal liability is at issue does not alter the

fact that reasonable interpretations of the act are entitled to deference.” Id. (citing Babbitt, 515 U.S. at

703–705, 115 S.Ct. 2407). And in In re Sealed Case,

223 F.3d 775 (D.C. Cir. 2000), we again declined to

forgo Chevron in a criminal context, holding that

“[d]eference is due as much in a criminal context as

in any other,” id. at 779 (citing Babbitt, 515 U.S. at

703–705, 115 S.Ct. 2407).

To be sure, the Supreme Court has signaled some

wariness about deferring to the government’s interpretations of criminal statutes. See Abramski, 573

U.S. at 191, 134 S.Ct. 2259; see also United States v.

Apel, 571 U.S. 359, 369, 134 S.Ct. 1144, 186 L.Ed.2d

75 (2014) (“[W]e have never held that the Government’s reading of a criminal statute is entitled to any

deference.”). But those statements were made outside

the context of a Chevron-eligible interpretation—that

is, outside the context of an agency “speak[ing] with

the force of law.” Mead, 533 U.S. at 229, 121 S.Ct.

2164. In Abramski, the Court declined to extend deference to informal guidance documents published by

the Bureau. See 573 U.S. at 191, 134 S.Ct. 2259. And

in Apel, the Court declined to defer to an interpretation contained in “Executive Branch documents” that

were “not intended to be binding.” 571 U.S. at 368,

134 S.Ct. 1144. When directly faced with the question

of Chevron’s applicability to an agency’s interpretation of a statute with criminal applications through a

A45

full-dress regulation, the Court adhered to Chevron.

See Babbitt, 515 U.S. at 704 n.18, 115 S.Ct. 2407.

That holding, and our court’s precedents, govern

us here and call for the application of Chevron. The

parties have identified no distinction between the

provision at issue in this case and the provisions with

criminal penalties to which Chevron deference has

been applied. The briefing contains nary a word suggesting any distinction between this case and prior

decisions applying Chevron in criminal contexts. And

neither Guedes nor counsel for the government offered any distinction even when specifically asked at

oral argument. See Oral Argument at 6:08–7:15,

45:45–49:00.

Nothing in the relevant statutory delegations of

authority, moreover, suggests a basis for denying

Chevron treatment for agency actions with criminal

implications The Supreme Court has instructed that

the inquiry turns on whether the “language of the

delegation provision” is sufficiently “broad” such that

it is “clear * * * the statute gives [the] agency * * *

power to enforce all provisions of the statute.” Gonzales v. Oregon, 546 U.S. 243, 258, 126 S.Ct. 904, 163

L.Ed.2d 748 (2006) (emphasis added). In Gonzales,

for example, the Court found that the Attorney General lacked power to interpret a particular criminal

provision of the Controlled Substances Act because

the delegation of rulemaking authority was too narrow and “did not delegate to the Attorney General

authority to carry out or effect all provisions of the

CSA.” Id. at 259, 126 S.Ct. 904 *26 (emphasis added).

By contrast, the two pertinent delegation provisions

in this case are framed in broad terms. See 18 U.S.C.

A46

§ 926(a) (delegating to Attorney General the power to

prescribe “such rules and regulations as are necessary to carry out the provisions of [the Gun Control

Act]”); 26 U.S.C. § 7805(a) (delegating to Attorney

General, see id. § 7801(a)(2)(A), the power to “prescribe all needful rules and regulations for the enforcement of [the National Firearms Act]”).

The statutory context bolsters the inference that

Congress intended those delegations to encompass

regulations with criminal implications. The Gun Control Act, found at Chapter 44 of Title 18, is a purely

criminal statute. See 18 U.S.C. § 924(a)(2). Yet

§ 926(a) expressly delegates to the Attorney General

the power to promulgate “such rules and regulations

as are necessary to carry out the provisions of th[at]

chapter.” Similarly, the National Firearms Act, found

at Chapter 53 of Title 26, has criminal applications.

See 18 U.S.C. § 924(a)(2); United States v. Thompson/Center Arms Co., 504 U.S. 505, 517, 112 S.Ct.

2102, 119 L.Ed.2d 308 (1992). The penalty for

“fail[ing] to comply with any provision of th[at] chapter” is a fine of up to $10,000, or imprisonment for up

to 10 years, or both. 26 U.S.C. § 5871. And yet

§ 7801(a)(2)(A) tasks the Attorney General with

“[t]he administration and enforcement of * * * Chapter 53,” including “prescrib[ing] all needful rules and

regulations for * * * enforcement.” Id. § 7805(a).

The plaintiffs rely on United States v. Thompson/Center Arms Co., in which the Supreme Court

applied the rule of lenity to an ambiguous provision

of the National Firearms Act. 504 U.S. at 517–518,

112 S.Ct. 2102. But Babbitt later made clear that the

Court in Thompson/Center had no occasion to apply

A47

Chevron: Thompson/Center, the Babbitt Court explained, “rais[ed] a narrow question concerning the

application of a statute that contain[ed] criminal

sanctions * * * where no regulation was present.”

Babbitt, 515 U.S. at 704 n.18, 115 S.Ct. 2407 (emphasis added). If anything, then, Babbitt implies that

Chevron should apply in a case—like this one—

involving an interpretation of the National Firearms

Act where a regulation is present.

The plaintiffs also cite United States v. McGoff,

831 F.2d 1071 (D.C. Cir. 1987), a pre-Babbitt decision

that interpreted the statute-of-limitations provision

of the Foreign Agents Registration Act. We observed

in passing that, “[n]eedless to say, in this criminal

context, we owe no deference to the Government’s interpretation of the statute.” Id. at 1080 n.17. As in

Thompson/Center, however, the McGoff Court had no

occasion to apply Chevron because the government

never asserted reliance on a regulation or other

Chevron-eligible instrument. See id.

At oral argument, the plaintiffs suggested that

permitting an agency’s interpretation to carry the

force of law in the criminal context would infringe the

separation of powers. See Oral Argument 6:51–6:58.

That suggestion is difficult to square with the Supreme Court’s decision in Touby v. United States, 500

U.S. 160, 111 S.Ct. 1752, 114 L.Ed.2d 219 (1991).

There, the Court upheld a delegation of legislative

authority to the Attorney General to schedule substances under the Controlled Substances Act against

a challenge under the nondelegation doctrine. Id. at

164, 111 S.Ct. 1752. The Court held that, in the criminal context, as in all contexts, the separation of pow-

A48

ers “does not prevent Congress from seeking assistance * * * from its coordinate Branches” so long as

Congress “lays down by legislative act an intelligible

principle to which the person or body authorized to

act is directed to conform.” Id. at 165, 111 S.Ct. 1752

(alterations *27 omitted) (quoting J.W. Hampton, Jr.,

& Co. v. United States, 276 U.S. 394, 409, 48 S.Ct.

348, 72 L.Ed. 624 (1928) ). And no party suggests

that such an intelligible principle is lacking in this

case.

In short, Congress delegated authority to administer the National Firearms Act and the Gun Control

Act to the Attorney General, and the Attorney General promulgated a legislative rule in the exercise of

that authority. Under binding precedent, Guedes and

Codrea have failed to demonstrate a likelihood of

success on their claim that the Rule is invalid just

because of its criminal-law implications.

(iii)

Relatedly, Guedes argue that Chevron is inapplicable because a different canon of interpretation, the

rule of lenity, should control instead. Under the rule

of lenity, “ambiguity concerning the ambit of criminal

statutes should be resolved in favor of lenity.” Rewis

v. United States, 401 U.S. 808, 812, 91 S.Ct. 1056, 28

L.Ed.2d 493 (1971). Guedes reasons that because

Chevron is premised on the existence of statutory

ambiguity, and because the rule of lenity resolves

ambiguity in favor of the defendant, there is no remaining ambiguity to which Chevron can apply.

It is true that the rule of lenity generally applies to

the interpretation of the National Firearms Act and

A49

the Gun Control Act. But in circumstances in which

both Chevron and the rule of lenity are applicable,

the Supreme Court has never indicated that the rule

of lenity applies first. In fact, the Court has held to

the contrary. In Babbitt, the Court squarely rejected

the argument that “the rule of lenity should foreclose

any deference to the Secretary’s interpretation of the

ESA because the statute includes criminal penalties.”

515 U.S. at 704 n.18, 115 S.Ct. 2407. The Court observed that it had “never suggested that the rule of

lenity should provide the standard for reviewing facial challenges to administrative regulations whenever

the governing statute authorizes criminal enforcement.” Id. The Court proceeded to apply Chevron deference. Id. at 703, 115 S.Ct. 2407.

Our precedent takes the same tack. In Kanchanalak, we expressly rebuffed the argument that Guedes

now presses: “To argue, as defendants do, that the

rule of lenity compels us to reject the FEC’s otherwise

reasonable interpretation of an ambiguous statutory

provision [under Chevron] is to ignore established

principles of law.” 192 F.3d at 1050 n.23 (citing Babbitt, 515 U.S. at 704 n.18, 115 S.Ct. 2407).

Those precedents are in line with the Supreme

Court’s characterization of the rule of lenity as a canon of “last resort.” The Court has instructed that

“[t]he rule comes into operation at the end of the process of construing what Congress has expressed, not

at the beginning as an overriding consideration of being lenient to wrongdoers.” Callanan v. United

States, 364 U.S. 587, 596, 81 S.Ct. 321, 5 L.Ed.2d 312

(1961). Accordingly, the rule of lenity applies only

“when the ordinary canons of statutory construction

A50

have revealed no satisfactory construction.” Lockhart

v. United States, ––– U.S. ––––, 136 S.Ct. 958, 968,

194 L.Ed.2d 48 (2016). And Chevron is a rule of statutory construction, insofar as it is a doctrine that

“constru[es] what Congress has expressed.” Callanan, 364 U.S. at 596, 81 S.Ct. 321.

Finally, our approach coheres with the rule of lenity’s purposes. The doctrine serves to ensure that “legislatures and not courts [are] defin[ing] criminal activity” and to secure “fair warning” about the content

of criminal law. United States v. Bass, 404 U.S. 336,

348, 92 S.Ct. 515, 30 L.Ed.2d 488 (1971) (internal

quotation *28 marks omitted). Chevron deference

vindicates both purposes.

First, Chevron is consistent with the separation of

powers, including for regulations defining criminal

activity, because delegations of legislative authority

in the criminal sphere are constitutional. See Touby,

500 U.S. at 165, 111 S.Ct. 1752. The parties would

have us disregard Congress’s textual delegations to

the agency and do the interpretive work instead.

That course, though, would not respect the notion

that “legislatures and not courts” should take the

lead. Bass, 404 U.S. at 348, 92 S.Ct. 515.

Second, Chevron promotes fair notice about the

content of criminal law. It applies only when, at Congress’s direction, agencies have followed “relatively

formal administrative procedure tending to foster the

fairness and deliberation that should underlie a pronouncement of such force.” Mead, 533 U.S. at 230,

121 S.Ct. 2164. Importantly, such procedures, which

generally include formal public notice and publication

A51

in the Federal Register, do not “provide such inadequate notice of potential liability as to offend the rule

of lenity.” Babbitt, 515 U.S. at 704 n.18, 115 S.Ct.

2407. Tellingly, there is no suggestion of inadequate

notice here. Rather, if the Rule is a valid legislative

rule, all are on notice of what is prohibited.

For substantially the same reasons, plaintiffs’

challenge under the Due Process Clause cannot succeed. To apply Chevron, Codrea notes, we must first

determine that the statute is ambiguous, but that, in

Codrea’s view, would imply that the statute is facially

void for vagueness. Codrea’s challenge is misconceived. A criminal statute is void for vagueness if it

fails to provide ordinary people “fair notice” of the

conduct it proscribes. Sessions v. Dimaya, ––– U.S. ––

––, 138 S.Ct. 1204, 1223, 200 L.Ed.2d 549 (2018). But

the promulgation of the Bump-Stock Rule through

notice-and-comment procedures afforded “fair notice”

of the prohibited conduct.

2

Having concluded that the Chevron framework is

applicable, we now proceed to examine the BumpStock Rule under it. We first ask whether the agencyadministered statute is ambiguous on the “precise

question at issue.” Chevron, 467 U.S. at 842, 104

S.Ct. 2778. If the statute’s meaning is unambiguous,

then we need go no further. But if we find ambiguity,

we proceed to the second step and ask whether the

agency has provided a “permissible construction” of

the statute. Id. at 843, 104 S.Ct. 2778. At that stage,

“the task that confronts us is to decide, not whether

[the agency’s interpretation is] the best interpreta-

A52

tion of the statute, but whether it represents a reasonable one.” Atl. Mut. Ins. Co. v. Comm’r, 523 U.S.

382, 389, 118 S.Ct. 1413, 140 L.Ed.2d 542 (1998).

The National Firearms Act and the Gun Control

Act both define “machinegun” to mean “any weapon

which shoots, is designed to shoot, or can be readily

restored to shoot, automatically more than one shot,

without manual reloading, by a single function of the

trigger.” 26 U.S.C. § 5845(b); see 18 U.S.C.

§ 921(a)(23). The definition of “machinegun” also includes “any part designed and intended solely and

exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun, and any combination of parts from which a

machinegun can be assembled if such parts are in the

possession or under the control of a person.” 26

U.S.C. § 5845(b).

The Bump-Stock Rule determines that semiautomatic rifles equipped with bump-stock-type devices

are “machineguns” *29 because they “function[ ] as

the result of a self-acting or self-regulating mechanism that allows the firing of multiple rounds”

through “a single pull of the trigger.” 83 Fed. Reg. at

66,553. Applying Chevron, we determine that the

statutory definition of “machinegun” is ambiguous

and the Bureau’s interpretation is reasonable. The

plaintiffs therefore are unlikely to succeed on the

merits of their claim that the Rule is out of step with

the statutory definition.

a

At Chevron’s first step, two features of the statutory definition of “machinegun” render it ambiguous.

A53

The first is the phase “single function of the trigger.”

The second is the word “automatically.” We discuss

them in that order.

(i)

As the district court recognized, the statutory

phrase “single function of the trigger” admits of more

than one interpretation. It could mean “a mechanical

act of the trigger.” Guedes, 356 F.Supp.3d at 130. Or

it could mean “a single pull of the trigger from the

perspective of the shooter.” Id.

The first interpretation would tend to exclude

bump-stock devices: while a semiautomatic rifle outfitted with a bump stock enables a continuous, highspeed rate of fire, it does so by engendering a rapid

bumping of the trigger against the shooter’s stationary finger, such that each bullet is fired because of a

distinct mechanical act of the trigger. The second interpretation would tend to include bump-stock devices: the shooter engages in a single pull of the trigger

with her trigger finger, and that action, via the operation of the bump stock, yields a continuous stream of

fire as long she keeps her finger stationary and does

not release it. See 83 Fed. Reg. at 66,519.

Neither of those interpretations is compelled (or

foreclosed) by the term “function” in “single function

of the trigger.” The word “function” focuses our attention on the “mode of action,” 4 Oxford English Dictionary 602 (1933), or “natural * * * action,” Webster’s New International Dictionary 876 (1933), by

which the trigger operates. But the text is silent on

the crucial question of which perspective is relevant.

A54

A mechanical perspective, for instance, might focus on the trigger’s release of the hammer, which

causes the release of a round. From that perspective,

a “single function of the trigger” yields a single round

of fire when a bump-stock device moves the trigger

back and forth. By contrast, from the perspective of

the shooter’s action, the function of pulling the trigger a single time results in repeated shots when a

bump-stock device is engaged. From that perspective,

then, a “single function of the trigger” yields multiple

rounds of fire.

In light of those competing, available interpretations, the statute contains a “gap for the agency to

fill.” Chevron, 467 U.S. at 843, 104 S.Ct. 2778.

Guedes argues that the phrase “single function of

the trigger” unambiguously compels a focus on the

trigger’s mechanical operation. He contends, for example, that “[r]egardless of the mechanism by which

the shooter acts * * * it is the movement of the trigger

releasing the hammer * * * that define[s] the boundaries of two distinct ‘single’ functions of the trigger.”

Guedes Br. 12–13. That argument begs the crucial

question of perspective. It may be reasonable to take

the view, as Guedes does, that the mechanical operation of the trigger is the lens through which to view

its function. But to establish a likelihood of success

on the merits, Guedes *30 and Codrea would have to

establish that reading the statute to mean a “single

pull of the trigger” by the shooter is impermissible.

They have not done so.

At Chevron’s first step, we do not ask which of

those interpretations is the better reading of the

A55

statute. Rather, we ask whether either of those interpretations is unambiguously “compel[led]” by the

statute, to the exclusion of the other one. Chevron,

467 U.S. at 860, 104 S.Ct. 2778. Here, we think the

answer is no.

Nor does Staples v. United States, 511 U.S. 600,

114 S.Ct. 1793, 128 L.Ed.2d 608 (1994), compel a particular interpretation of “single function of the trigger.” There, in a footnote, the Court observed that a

weapon is “automatic” if it “fires repeatedly with a

single pull of the trigger”—“[t]hat is, [if] once its trigger is depressed, the weapon will automatically continue to fire until its trigger is released or the ammunition is exhausted.” Id. at 602 n.1, 114 S.Ct. 1793.

The Court’s description, then, speaks both in terms of

a “single pull of the trigger” and a “release[ ]” of the

trigger, id. (emphasis added), which ultimately sheds

limited light on the choice between the two competing

understandings of “function of the trigger” that are at

issue here. Regardless, the precise definition of “single function of the trigger” was not at issue in Staples. See id. at 602, 114 S.Ct. 1793. And the Court did

not purport to exclude any interpretation as foreclosed by the statute. Cf. Nat’l Cable & Telecomms.

Ass’n v. Brand X Internet Servs., 545 U.S. 967, 996,

125 S.Ct. 2688, 162 L.Ed.2d 820 (2005).

(ii)

Similarly, the statutory term “automatically” admits of multiple interpretations. The statute speaks

in terms of a “weapon which shoots * * * automatically more than one shot, without manual reloading, by

a single function of the trigger.” 26 U.S.C. § 5845(b);

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see 18 U.S.C. § 921(a)(23). The term “automatically”

does not require that there be no human involvement

to give rise to “more than one shot.” Rather, the term

can be read to require only that there be limited human involvement to bring about more than one shot.

See, e.g., Webster’s New International Dictionary 157

(defining “automatically” as the adverbial form of

“automatic”); id. at 156 (defining “automatic” as “selfacting or self-regulating,” especially applied to “machinery or devices which perform parts of the work

formerly or usually done by hand” (emphasis added)).

But how much human input in the “self-acting or

self-regulating” mechanism is too much?

The plaintiffs would read the phrase “by a single

function of the trigger” to provide “the starting and

the ending point of just how much human input is allowable.” Codrea Br. 14. In their view, then, a gun

cannot be said to fire “automatically” if it requires

both a single pull of the trigger and constant pressure on the gun’s barrel, as a bump-stock device requires. We are unpersuaded. After all, a quite common feature of weapons that indisputably qualify as

machine guns is that they require both a single pull

of the trigger and the application of constant and

continuing pressure on the trigger after it is pulled.

We know, therefore, that the requirement of some

measure of additional human input does not render a

weapon nonautomatic. To purloin an example from

the district court: an “automatic” sewing machine

still “requires the user to press a pedal and direct the

fabric.” Guedes, 356 F.Supp.3d at 131 (emphasis added).

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That workaday example illustrates another, perhaps more natural, reading of “automatically”: the

“automatic[ ]” mechanism need only be “set in motion” by a single function of the trigger. *31 United

States v. Olofson, 563 F.3d 652, 658 (7th Cir. 2009)

(emphasis added); see also United States v. Evans,

978 F.2d 1112, 1113 n.2 (9th Cir. 1992) (“ ‘[B]y a single function of the trigger’ describes the action that

enables the weapon to ‘shoot automatically without

manual reloading, not the ‘trigger’ mechanism.” (ellipses omitted)). That is, rather than reading the

phrase “by a single function of the trigger” to mean

“by only a single function of the trigger,” the phrase

can naturally be read to establish only the preconditions for setting off the “automatic” mechanism,

without foreclosing some further degree of manual

input such as the constant forward pressure needed

to engage the bump stock in the first instance. And if

so, then the identified ambiguity endures. How much

further input is permitted in the mechanism set in

motion by the trigger? The statute does not say.

In sum, the statutory definition of “machinegun”

contains two central ambiguities, both of which the

agency has attempted to construe. We therefore proceed to Chevron’s second step.

b

At the second step, “the question for the court is

whether the agency’s [construction] is based on a

permissible construction of the statute.” Chevron, 467

U.S. at 843, 104 S.Ct. 2778. Guedes and Codrea are

not likely to succeed in showing that the agency has

impermissibly interpreted both ambiguities.

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The Bureau’s interpretation of “single function of

the trigger” to mean “single pull of the trigger” is a

permissible reading of the statute. The Bureau is better equipped than we are to make the pivotal policy

choice between a mechanism-focused and shooterfocused understanding of “function of the trigger.”

And the Bureau’s interpretation comports with how

some courts have read the statute, which is a strong

sign of reasonableness. In Akins v. United States, 312

F. App’x 197 (11th Cir. 2009), for example, the Eleventh Circuit held that the Bureau’s reading of “single

function of the trigger” to mean “single pull of the

trigger” was “consonant with the statute and its legislative history.” Id. at 200. The court relied on that

definition to conclude that an “Accelerator”—a type of

bump stock—was reasonably classified as a machine

gun. Id. And “single pull of the trigger” has been the

definition the agency has employed since 2006. See 83

Fed. Reg. at 66,543. The Rule’s interpretation also

accords with how the phrase “single pull of the trigger” was understood at the time of the enactment of

the National Firearms Act. See 83 Fed. Reg. at

66,518. The Rule cites a congressional hearing for the

National Firearms Act in which the then-president of

the National Rifle Association testified that the term

“machine gun” included any gun “capable of firing

more than one shot by a single pull of the trigger, a

single function of the trigger.” 83 Fed. Reg. 66,518.

And the House Report accompanying the bill that

eventually became the National Firearms Act states

that the bill “contains the usual definition of a machine gun as a weapon designed to shoot more than

one shot * * * by a single pull of the trigger.” H.R.

Rep. No. 73-1780, at 2 (1934).

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The Bureau’s interpretation of “automatically” is

permissible too. The Rule’s requirement of a “selfacting or self-regulating mechanism” demands a significant degree of autonomy from the weapon without

mandating a firing mechanism that is completely autonomous. That definition accords with the everyday

understanding of the word “automatic.” And it focuses the inquiry about what needs to be automated

right where the statute does: the ability of the trigger

function to produce “more than *32 one shot, without

manual reloading.” 26 U.S.C. § 5845(b). It also tracks

the interpretation reached by the Seventh Circuit in

United States v. Olofson, 563 F.3d 652 (7th Cir.

2009), in which the court interpreted the term to require a “self-acting mechanism” without requiring

more, id. at 658.

The plaintiffs argue that the Bureau’s definition of

“machinegun” is unreasonable because it has the effect of reaching all semiautomatic rifles. Because

“virtually all” semiautomatic rifles can be “bumpfired” with the use of common household items, the

plaintiffs contend, the Bureau’s definition covers even

unmodified semiautomatic rifles, which renders it

unreasonable. Guedes Br. 18.

The Rule explains why the plaintiff’s understanding is incorrect, and the Rule’s explanation in that

regard is reasonable. See 83 Fed. Reg. at 66,532–

66,534. The Bureau acknowledges that bump firing—

a technique using a stable point like a belt loop to

approximate the function of a bump stock—is possible with semiautomatic weapons. See id. at 66,533.

But even when a semiautomatic weapon is bump

fired using an object like a belt loop or a rubber band,

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the Bureau explained, the weapon does not fire “automatically” because there is no “self-acting or selfregulating mechanism.” Rubber bands and their ilk

do not “capture and direct the recoil energy” to “harness[ ] [it] as part of a continuous back-and-forth cycle.” Id. at 66,533. Rather, “the shooter must do so”

herself. Id. Bump firing without the aid of a bumpstock-type device is therefore “more difficult” because

it relies solely on the shooter “to control the distance

that the firearm recoils and the movement along the

plane on which the firearm recoils.” Id.

Bump stocks, on the other hand, are specifically

designed to “direct[ ] the recoil energy of the discharged rounds * * * in constrained linear rearward

and forward paths.” Id. at 66,532. By capturing the

recoil energy of the gun and directing it through a

specified “distance” and along a specified “plane,”

bump stocks “incorporate[ ] a self-acting or selfregulating component” that would otherwise be absent. Id. at 66,533. Thus, belt loops, unlike bump

stocks, do not transform semiautomatic weapons into

statutory “machineguns.” Or so the Bureau reasonably concluded in the Rule.

“If a statute is ambiguous, and if the implementing

agency’s construction is reasonable, Chevron requires

a federal court to accept the agency’s construction of

the statute, even if the agency’s reading differs from

what the court believes is the best statutory interpretation.” Brand X, 545 U.S. at 980, 125 S.Ct. 2688.

Here, the Bump-Stock Rule sets forth a permissible

interpretation of the statute’s ambiguous definition of

“machinegun.” It therefore merits our deference.

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C

In addition to their argument that the Rule is incompatible with the statutory definition of a machine

gun, the plaintiffs also contend that the Rule is arbitrary and capricious. Agency action is arbitrary or

capricious if “the agency has relied on factors which

Congress has not intended it to consider, entirely

failed to consider an important aspect of the problem,

offered an explanation for its decision that runs counter to the evidence before the agency, or is so implausible that it could not be ascribed to a difference in

view or the product of agency expertise.” Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto. Ins. Co., 463

U.S. 29, 43, 103 S.Ct. 2856, 77 L.Ed.2d 443 (1983).

Here, the plaintiffs claim that, for various reasons,

the Rule is arbitrary in applying the statutory definition of “machinegun” to *33 bump stocks. None of

their claims is likely to succeed.

First, the plaintiffs argue that the Rule fundamentally mischaracterizes the operation of bump-stock

devices. In their view, the Rule disregards that, for

each shot, “the shooter must manually and volitionally push the trigger into [a] stationary finger.” Guedes

Br. 24. It is true that, for a bump-stock-equipped device to repeatedly fire, the shooter must keep the

bumpstock engaged by maintaining constant forward

pressure on the gun. But in the Rule, the Bureau correctly describes the operation of bump-stock-equipped

devices: the shooter must “maintain[ ] constant forward pressure [on the gun] with the non-trigger

hand” in order to maintain continuous fire. 83 Fed.

Reg. at 66,532. The bump stock takes advantage of

the gun’s recoil, channeled into a linear back-and-

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forth cycle, to permit the shooter to fire continuously

by maintaining steady forward pressure on the gun.

There is thus no disagreement about the basic mechanics of bump-stock devices.

Guedes takes particular issue with the Rule’s

characterization of recoil. He argues that bumpstock-equipped devices cannot “harness[ ] the recoil

energy of the firearm” because they do not use “a device such as a spring or hydraulics * * * [to] automatically absorb the recoil and use this energy to activate

itself.” Guedes Br. 16–17. But the Rule does not

adopt such an impoverished definition of “automatically.” The Rule requires only that the recoil be used

in service of a “self-acting or self-regulating mechanism.” A bump stock “direct[s] the recoil energy of the

discharged rounds * * * in constrained linear rearward and forward paths,” 83 Fed. Reg. at 66,518

(quoting 83 Fed. Reg. at 13,443), which qualifies as a

“self-regulating mechanism.”

Second, the plaintiffs assert that the Rule is arbitrary because its definition encompasses all semiautomatic weapons. That argument is largely redundant of the plaintiffs’ Chevron step two argument to

the same effect, which we have already addressed.

We dispose of this iteration of the same argument on

the same grounds: Bump stocks, unlike commonplace

household objects, are specifically designed to “direct[

] the recoil energy of the discharged rounds * * * in

constrained linear rearward and forward paths.” Id.

Bump stocks, unlike household objects, are machine

guns because they alone involve a “self-acting or selfregulating mechanism.” Id.

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Third, the plaintiffs submit that the Rule arbitrarily excludes binary-trigger guns from its definition of

“machinegun.” Binary-trigger guns shoot one round

when the trigger is pulled and another round when

the trigger is released. 83 Fed. Reg. at 66,534. The

Rule concludes that such devices are not machine

guns because the second shot is “the result of a separate function of the trigger.” Id. The plaintiffs argue

that if the release of the trigger is a separate function, the operation of a bump stock—which requires

the shooter to keep the trigger finger stationary while

steadily pushing the gun forward into the finger—

must also involve multiple functions of the trigger.

But the Rule reasonably distinguishes binary-trigger

guns on the ground that they require a second act of

volition with the trigger finger. The release of a trigger is a volitional motion. But merely holding the

trigger finger stationary—which is what operation of

a bump stock entails—is not.

Fourth, Guedes contends that the Rule is arbitrary

because its definition of “automatically” is ambiguous. The Rule’s definition, Guedes notes, does not

specify how much manual input is too much. But *34

the existence of latent ambiguity does not render an

interpretation arbitrary or capricious. Agencies are

permitted to promulgate regulations interpreting

ambiguous statutes without having to resolve all possible ambiguity.

Fifth, Codrea argues that the Rule arbitrarily

failed to consider reliance interests, “an important

aspect of the problem.” State Farm, 463 U.S. at 43,

103 S.Ct. 2856. It is true that “the APA requires an

agency to provide more substantial justification when

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* * * its prior policy has engendered serious reliance

interests that must be taken into account.” Perez, 135

S.Ct. at 1209 (quoting FCC v. Fox Television Stations,

Inc., 556 U.S. 502, 515, 129 S.Ct. 1800, 173 L.Ed.2d

738 (2009)). But the only reliance interest identified

by Codrea is the pecuniary interest of current possessors of bumpstock devices. See Codrea Br. 19–20 & 19

n.4; Comment of Maryland Shall Issue at 6. And in

the Rule, the Bureau engaged in a cost-benefit analysis that considered, among other things, the cost incurred by owners of bump-stock devices. See 83 Fed.

Reg. at 66,546.

Finally, Guedes argues that the Rule is arbitrary

because it is the product of “naked political desire.”

Guedes Br. 18. Insofar as Guedes means to claim that

the Rule arises from political considerations, he is

surely right. All would agree that the Bureau enacted

this Rule in response to the urging of “the President,

Members of Congress, and others,” as part of an

“immediate and widespread” outcry in the wake of

the 2017 mass shooting in Las Vegas. Guedes, 356

F.Supp.3d at 120, 123. The Rule itself describes its

origins in a memorandum issued by President Trump

to then–Attorney General Sessions “direct[ing] the

Department of Justice * * * ‘as expeditiously as possible, to propose for notice and comment a rule banning all devices that turn legal weapons into machineguns.’ ” 83 Fed. Reg. at 66,516–66,517 (quoting

Application of the Definition of Machinegun to ‘Bump

Fire’ Stocks and Other Similar Devices, 83 Fed. Reg.

7,949 (Feb. 23, 2018)). But that is hardly a reason to

conclude that the Rule is arbitrary. Presidential administrations are elected to make policy. And “[a]s

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long as the agency remains within the bounds established by Congress, it is entitled to assess administrative records and evaluate priorities in light of the

philosophy of the administration.” Nat’l Ass’n of

Home Builders v. EPA, 682 F.3d 1032, 1043 (D.C. Cir.

2012) (quoting State Farm, 463 U.S. at 59, 103 S.Ct.

2856 (Rehnquist, J., concurring in part and dissenting in part)).

Guedes might instead mean to contend that the

Bureau was so eager to enact the policy preferences

of the President that it failed to engage in reasoned

consideration of the issues. The central purpose of

arbitrary or capricious review is to assure that the

agency has engaged in “reasoned decisionmaking.”

State Farm, 463 U.S. at 52, 103 S.Ct. 2856. We ordinarily do so, however, by examining whether the

agency has “articulate[d] a satisfactory explanation

for its actions.” Id. at 43, 103 S.Ct. 2856. Here, the

agency has articulated a satisfactory explanation for

the Bump-Stock Rule. And the administrative record

reflects that the agency kept an open mind throughout the notice-and-comment process and final formulation of the Rule. See Air Transp. Ass’n of Am. v.

Nat’l Mediation Bd., 663 F.3d 476, 487–488 (D.C. Cir.

2011); C&W Fish Co. v. Fox, 931 F.2d 1556, 1564–

1565 (D.C. Cir. 1991). In the absence of any actual

evidence of delinquent conduct, we accord the Bureau

a “presumption of regularity” in its promulgation of

the Rule. Citizens to Pres. Overton Park, Inc. v. Volpe,

401 U.S. 402, 415, 91 S.Ct. 814, 28 L.Ed.2d 136

(1971).

*35

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D

Finally, Codrea argues that the Rule must be vacated because it is impermissibly retroactive, violating both 26 U.S.C. § 7805(b)’s bar on retroactive

rulemaking and the Ex Post Facto Clause. That claim

has been forfeited because the plaintiffs failed to

raise it in the district court. The Rule, at any rate,

cannot be characterized as retroactive: As we have

explained, the Rule itself made clear that the possession of bump stocks would become unlawful only after the effective date.

Further, it matters not that the government’s post

hoc litigation strategy has been to characterize the

Rule as merely interpretive and, consequently, backward looking. Irrespective of that litigating position,

the Rule is legislative in character and therefore

purely prospective. Any criminal consequences did

not attach until the Rule’s effective date. And notice

to the public has been clear and explicit.

*****

The plaintiffs have failed to establish a likelihood

of success both for their challenge to Acting Attorney

General Whitaker’s appointment and for their objections to the substantive validity of the Rule. For the

foregoing reasons, we affirm the district court’s denial of a preliminary injunction.

So ordered.

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Karen Lecraft Henderson, Circuit Judge, concurring in part and dissenting in part:

Federal law makes it a crime to possess or transfer

a “machinegun.” 18 U.S.C. § 922(o)(1). This case is

about a Bureau of Alcohol, Tobacco, Firearms, and

Explosives (ATF) regulation that reinterprets the

statutory definition of “machinegun” and applies it to

all bump stock type devices. Bump-Stock-Type Devices, 83 Fed. Reg. 66,514 (Dec. 26, 2018) (Bump Stock

Rule or Rule). Individual firearms owners and nonprofit groups sued the ATF, seeking preliminary injunctive relief to stop the Bump Stock Rule from going into effect. The issue before us on this expedited

appeal of the district court’s denial of preliminary injunctive relief, Guedes v. ATF, 356 F.Supp.3d 109

(D.D.C. 2019), is whether the plaintiffs are likely to

succeed on the merits of their challenge to the Bump

Stock Rule as contrary to the statutory definition of

“machinegun.” Unlike my colleagues, I believe the

Bump Stock Rule does contradict the statutory definition and, respectfully, part company with them on

this issue.1

A “machinegun” is a firearm “which shoots ... automatically more than one shot, without manual reloading, by a single function of the trigger.” 26 U.S.C.

§ 5845(b). In my view, the Rule impermissibly adds to

the language “automatically ... by a single function of

the trigger,” including within its definition a firearm

that shoots more rapidly only by a single function of

the trigger and the shooter’s additional manual in-

1 I concur in Parts II and III.A of the majority opinion.

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put. The statute specifies a single function; the Rule

specifies a single function plus. “Whether the Government interprets a criminal statute too broadly (as

it sometimes does) or too narrowly,” we have “an obligation to correct its error.” Abramski v. United

States, 573 U.S. 169, 191, 134 S.Ct. 2259, 189

L.Ed.2d 262 (2014).

I. BACKGROUND

A. Statutory Framework

The National Firearms Act of 1934, Pub. L. No. 73474, 48 Stat. 1236, “imposes strict registration requirements on statutorily *36 defined ‘firearms.’ ”

Staples v. United States, 511 U.S. 600, 602, 114 S.Ct.

1793, 128 L.Ed.2d 608 (1994). In the 1934 legislation,

the Congress defined “machinegun” as a specific type

of “firearm.” The original text defined a “machinegun” as “any weapon which shoots, or is designed to shoot, automatically or semiautomatically,

more than one shot, without manual reloading, by a

single function of the trigger.” National Firearms Act

§ 1(b) (emphasis added). A few decades later, the Gun

Control Act of 1968, Pub. L. No. 90-618, 82 Stat.

1213, amended the definition in two key ways, deleting the phrase “or semiautomatically” and including

“parts” designed and used to “convert a weapon into a

machinegun.”2 Gun Control Act, tit. II, § 201, 82 Stat.

2 It thus extends to “the frame or receiver of any such weap-

on, any part designed and intended solely and exclusively, or

combination of parts designed and intended, for use in converting a weapon into a machinegun, and any combination of parts

from which a machinegun can be assembled if such parts are in

the possession or under the control of a person.” 26 U.S.C. §

5845(b).

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at 1231 (codified at 26 U.S.C. § 5845(b)). The definition of “machinegun” in effect today includes “any

weapon which shoots, is designed to shoot, or can be

readily restored to shoot, automatically more than

one shot, without manual reloading, by a single function of the trigger.” 26 U.S.C. § 5845(b).

The Firearms Owners’ Protection Act of 1986 (Act),

Pub. L. No. 99-308, 100 Stat. 449, effectively banned

private ownership of machine guns. Firearms Owners’ Protection Act, § 102(9) (codified at 18 U.S.C.

§ 922(o)(1)). The Act makes it “unlawful for any person to transfer or possess a machinegun,” 18 U.S.C.

§ 922(o)(1), and “machinegun” has “the meaning given ... in section 5845(b) of the National Firearms

Act,” id. § 921(a)(3). A person who “knowingly” violates the ban can be “fined ... [or] imprisoned not

more than 10 years, or both.” Id. § 924(a)(2). The ban

has two exceptions: one for “a transfer to or by, or

possession by or under the authority of” the federal

government or a state government, id. § 922(o)(2)(A),

and the other grandfathers any “machinegun” lawfully possessed before the Act went into effect, id.

§ 922(o)(2)(B).

B. History of Bump Stock Regulation

Firearms manufacturers have created various devices that allow a lawful semiautomatic rifle to perform more rapidly. A bump stock is one such device.

It replaces the standard stock of a rifle—the part that

rests against the shooter’s shoulder. A bump stock

“free[s] the weapon to slide back and forth rapidly.”

Bump-Stock-Type Devices, 83 Fed. Reg. at 66,516.

The sliding motion allows a shooter to increase his

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rate of fire. A rifle produces recoil energy upon firing.

The bump stock helps direct the firearm’s recoil and

convert the recoil energy into rapidly firing rounds. It

works like this: the shooter pulls the trigger; the recoil causes the firearm to slide backward; the shooter

maintains backward pressure on the trigger with the

index finger of his shooting hand and forward pressure on the barrel with his other hand. Id. This process causes the firearm to slide back and forth rapidly, bumping the shooter’s stationary trigger finger

and thereby firing additional rounds. Id.

Some bump stock devices use only the shooter’s

physical pressure to channel the recoil energy and do

not include springs or mechanical parts. Id. For these

devices, a single pull of the trigger alone—without

the shooter’s additional forward pressure—does not

cause the firearm to shoot more than one round. Video evidence in *37 the record makes this clear.3 In

the video, the shooter fires a rifle equipped with a

non-mechanical bump stock. The shooter holds the rifle with one hand, the trigger hand. He then pulls the

trigger and the rifle fires a single shot. Without his

other hand’s forward pressure on the barrel, the rifle

equipped with a non-mechanical bump stock fires only a single round with each pull of the trigger.

The ATF first classified a bump stock type device

in 2002, concluding that it was not a “machinegun.”

Id. at 66,517. The classification involved a product

called the Akins Accelerator, a bump stock that used

internal springs. “To operate the device, the shooter

3 The declaration of Rick Vasquez, a former senior ATF Technical Expert, attests to the accuracy of the video evidence.

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initiated an automatic firing sequence by pulling the

trigger one time, which in turn caused the rifle to recoil within the stock, permitting the trigger to lose

contact with the finger and manually reset.” Id.

“Springs in the Akins Accelerator then forced the rifle

forward, forcing the trigger against the finger, which

caused the weapon to discharge the ammunition.” Id.

The ATF interpreted the statutory language “single

function of the trigger” to mean a “single movement

of the trigger.” Id. A semi-automatic rifle fires only a

single round each time the trigger is pulled and reset.

According to the ATF, because the Akins Accelerator

did not modify how a semiautomatic rifle’s trigger

“moves” with each shot, it was not a “machinegun.”

In 2006, the ATF reclassified the Akins Accelerator as a “machinegun.” It reinterpreted the phrase

“single function of the trigger” from “single movement

of the trigger” to “single pull of the trigger.” Id. The

reinterpretation made all the difference. Once a

shooter pulls and maintains pressure on the trigger,

the internal springs of the Akins Accelerator start an

automatic sequence that keeps the rifle firing until

the shooter removes his finger or depletes the ammunition. The firing of multiple rounds based on a

single continuous pull of the trigger made the device

a “machinegun” under the ATF’s reinterpretation.

The Akins Accelerator inventor challenged the ATF’s

changed reading in federal district court (M.D. Fla.),

arguing that the Agency misinterpreted the statutory

definition of “machinegun.” The district court upheld

the ATF’s determination and the Eleventh Circuit affirmed. Akins v. United States, 312 F. App’x 197 (11th

Cir. 2009). The appellate court concluded that “the

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interpretation by the Bureau that the phrase ‘single

function of the trigger’ means a ‘single pull of the

trigger’ is consonant with the [National Firearms

Act] and its legislative history.” Id. at 200 (quoting 26

U.S.C. § 5845(b)).

“In ten letter rulings between 2008 and 2017, ATF

applied the ‘single pull of the trigger’ interpretation

to other bumpstock-type devices” and determined

that none qualified as a “machinegun.” Bump-StockType Devices, 83 Fed. Reg. at 66,517. Although each

device fired more than one round with a single pull of

the trigger, the ATF concluded that none was a “machinegun” because the firing sequence did not occur

“automatically.” Unlike the Akins Accelerator, the

devices did not rely on springs or mechanical parts.

In order to use them, “the shooter [had to] apply constant forward pressure with the non-shooting hand

and constant rearward pressure with the shooting

hand.” Joint Appendix (J.A.) at 278. Thus, the ATF

drew a distinction between a bump stock with mechanical parts like springs that cause a more rapid

firing sequence and a bump *38 stock that uses both

of the shooter’s hands to do the same. E.g., Letter

from Richard W. Marianos, Assistant Dir. Pub. and

Governmental Affairs, to Congressman Ed Perlmutter (April 16, 2013), reprinted at J.A. 281–82.

C. The Bump Stock Rule

In October 2017, a gunman armed with several

semiautomatic rifles killed 58 people and wounded

500 more in Las Vegas, Nevada. The rifles were

equipped with bump stock devices, which “were readily available in the commercial marketplace through

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online sales directly from the manufacturer, and

through multiple retailers.” Bump-Stock-Type Devices, 83 Fed. Reg. at 66,514. Using these devices, the

gunman was able to fire hundreds of rounds in a

matter of minutes. Within months, the ATF began to

promulgate a regulation to classify any bump stock

type device as a “machinegun.” President Trump directed the DOJ to “dedicate all available resources to

... propos[ing] for notice and comment a rule banning

all devices that turn legal weapons into machineguns.” Application of the Definition of Machinegun to “Bump Fire” Stocks and Other Similar

Devices, 83 Fed. Reg. 7,949 (Feb. 20, 2018).

In December 2018, the ATF promulgated the

Bump Stock Rule.4 Bump-Stock-Type Devices, 83 Fed.

Reg. at 66,514. It declares that all bump stock type

devices “are ‘machineguns’ as defined by the National

Firearms Act of 1934 and the Gun Control Act of

1968 because such devices allow a shooter of a semiautomatic firearm to initiate a continuous firing cycle

with a single pull of the trigger.” Id. According to the

Rule, the “devices convert an otherwise semiautomatic firearm into a machinegun by functioning as a selfacting or self-regulating mechanism that harnesses

the recoil energy of the semiautomatic firearm in a

manner that allows the trigger to reset and continue

firing without additional physical manipulation of the

trigger by the shooter.” Id. (emphasis added). Thus,

“a semiautomatic firearm to which a bump-stock de4 The Rule amends three separate regulations, 27 C.F.R.

§§ 447.11, 478.11, 479.11, reinterpreting with identical language

the statutory definition of “machinegun” in each.

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vice is attached is able to produce automatic fire with

a single pull of the trigger.” Id.

The Bump Stock Rule was scheduled to go into effect on March 26, 2019.5 There were then an estimated 280,000 to 520,000 previously legal bump stocks in

circulation in the United States. See Bump-StockType Devices, 83 Fed. Reg. 13,442, 13,451 (March 29,

2018). Under the Rule, “[b]ump-stock-type devices ...

possessed by individuals [had] to be destroyed or

abandoned” before March 26. Bump-Stock-Type Devices 83 Fed. Reg. at 66,546. Anyone who possesses or

transports the device after that date faces criminal

liability. 18 U.S.C. § 922(o)(1).

D. Procedural History

The plaintiffs, five individual firearms owners and

four non-profit organizations, challenge the Bump

Stock Rule’s legality on several grounds. Their primary challenge is that the Rule misinterprets the

statutory definition of “machinegun” and mistakenly

extends that definition to cover bump stock type devices. They also attack the Rule for alleged procedural gaps in the rulemaking process and for taking

property without just compensation in violation of

the Fifth Amendment’s Due Process *39 Clause. Finally, the plaintiffs contend that former Acting Attorney General Matthew Whitaker was not properly

appointed to his position and thus lacked authority to

5 After hearing argument on March 22, 2019, we issued an

administrative order staying the Rule’s effective date but only

as to the plaintiffs. Per Curiam Order, Guedes v. ATF, No. 195042 (D.C. Cir. March 23, 2019).

A75

approve the Rule. The plaintiffs separately moved for

preliminary injunctive relief.

The district court consolidated and denied the motions. “A plaintiff seeking a preliminary injunction

must establish that he is likely to succeed on the

merits, that he is likely to suffer irreparable harm in

the absence of preliminary relief, that the balance of

equities tips in his favor, and that an injunction is in

the public interest.” Winter v. Nat. Res. Def. Council,

Inc., 555 U.S. 7, 20, 129 S.Ct. 365, 172 L.Ed.2d 249

(2008). The district court determined that the Rule

reasonably interprets “machinegun” to include bump

stock devices. It also rejected the plaintiffs’ other

challenges either as unlikely to succeed on the merits

or as unsuitable for equitable relief. Accordingly, the

district court denied relief without reaching the other

three preliminary-injunction factors. The plaintiffs

then filed a timely interlocutory appeal. See 28 U.S.C.

§ 1292(a)(1).

II. ANALYSIS

A. STANDARD OF REVIEW

The district court’s denial of preliminary injunctive relief rests on its legal determination that the

Bump Stock Rule does not misinterpret or misapply

the statutory definition of “machinegun.” Our review

is therefore de novo. City of Las Vegas v. Lujan, 891

F.2d 927, 931–32 (D.C. Cir. 1989) (de novo review of

denial of preliminary injunctive relief where “district

judge did not make any factual determinations ...

since he was sitting in appellate review of agency action” and “denied the preliminary injunction because,

and only because, he believed the [agency] was likely

A76

to succeed on the merits”); see also Athens Cmty.

Hosp., Inc. v. Shalala, 21 F.3d 1176, 1178 (D.C. Cir.

1994) (“Upon the issue whether an administrative

regulation is lawful, we do not defer to the judgment

of the district court.”).

Despite the parties’ agreement that the de novo

standard of review applies, my colleagues, like the

district court, see Guedes, 356 F.Supp.3d at 126–27,

nonetheless review the ATF’s interpretation under

the two-step framework set out in Chevron, U.S.A.,

Inc. v. Natural Resources Defense Council, Inc., 467

U.S. 837, 842–43, 104 S.Ct. 2778, 81 L.Ed.2d 694

(1984).6 But the United States Supreme Court has

recently clarified whether the Chevron framework

applies to a statute—and, by extension a rule—

enforced by a criminal sanction. United States v.

Apel, 571 U.S. 359, 369, 134 S.Ct. 1144, 186 L.Ed.2d

75 (2014) (“[W]e have never held that the Govern6 Even under Chevron, “[a]n agency construction of a statute

cannot survive judicial review if a contested regulation reflects

an action that exceeds the agency’s authority.” Aid Ass’n for Lutherans v. U.S. Postal Serv., 321 F.3d 1166, 1174 (D.C. Cir.

2003). Because the Bump Stock Rule exceeds the ATF’s authority by veering from the plain meaning of the statute, I would

reach the same conclusion whether Chevron step one or de novo

review applies.

In reply to my colleagues’ insistence that, at the rulemaking

stage, the ATF emphasized its reliance on Chevron, Maj. Op. at

18–19, I would note that the ATF in fact declared that the

Rule’s interpretations of “single function of the trigger” and “automatically” “accord with the plain meaning of those terms.”

Bump-Stock-Type Devices, 83 Fed. Reg. at 66,527 (emphasis

added). Its “fallback” position at that stage was “even if those

terms are ambiguous, this rule rests on a reasonable construction of them.” Id. (emphasis added).

A77

ment’s reading of a criminal statute is entitled to any

deference.”). In another recent decision, Abramski v.

United States, the ATF had taken one view of 18

U.S.C. § 922(a)(6) for “almost two decades,” *40 concluding that a straw purchaser’s “misrepresentation”

counted as “material” under the statute notwithstanding the true buyer could legally possess a gun.

573 U.S. at 191, 134 S.Ct. 2259. The defendant pointed out that the ATF had until 1995 taken the opposite position, requiring the true buyer to be ineligible

to possess a gun in order to make the straw purchaser’s misrepresentation “material.” Id. The Supreme

Court responded that the “ATF’s old position [is] no

more relevant than its current one—which is to say,

not relevant at all.” Id. Indeed, “[w]hether the Government interprets a criminal statute too broadly (as

it sometimes does) or too narrowly (as the ATF used

to in construing § 922(a)(6)), a court has an obligation

to correct its error.” Id. In its Apel and Abramski decisions, then, “[t]he Supreme Court has expressly instructed us not to apply Chevron deference when an

agency seeks to interpret a criminal statute.”

Gutierrez-Brizuela v. Lynch, 834 F.3d 1142, 1156

(10th Cir. 2016) (Gorsuch, J., concurring).

My colleagues believe that this case is different because the 26 U.S.C. § 5845(b) definition of “machinegun” has both civil7 and criminal8 enforcement

7 See 26 U.S.C. § 5872(a) (“Any firearm involved in any viola-

tion of the provisions of this chapter shall be subject to seizure

and forfeiture, and (except as provided in subsection (b)) all the

provisions of internal revenue laws relating to searches, seizures, and forfeitures of unstamped articles are extended to and

A78

implications. They reach their conclusion regarding

the applicable standard of review based in part on a

footnote in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687, 115 S.Ct.

2407, 132 L.Ed.2d 597 (1995). That case involved a

regulation interpreting the definition of “harm” under

the Endangered Species Act, a regulation with both

criminal and civil enforcement implications. Id. at

704, 115 S.Ct. 2407 n.18. The Supreme Court deferred to the Secretary of the Interior’s interpretation

under Chevron. Id. at 703–04, 115 S.Ct. 2407. The

majority reads Babbitt—and some of our precedent—

to establish a bright-line rule that any regulation

with both civil and criminal enforcement provisions

merits Chevron deference. Maj. Op. at 23–25; see In

re Sealed Case, 223 F.3d 775, 779 (D.C. Cir. 2000);

United States v. Kanchanalak, 192 F.3d 1037, 1047

n.17 (D.C. Cir. 1999).9

made to apply to the articles taxed under this chapter, and the

persons to whom this chapter applies.”).

8 See 18 U.S.C. § 922(o)(1) (“[I]t shall be unlawful for any per-

son to transfer or possess a machinegun.”); 18 U.S.C.

§ 921(a)(23) (“The term ‘machinegun’ has the meaning given

such term in section 5845(b) of the National Firearms Act (26

U.S.C. 5845(b)).”); 18 U.S.C. § 924(a) (establishing penalties for

“knowing[ ]” or “willful[ ]” violation of, inter alia, section

922(o)(1)’s ban on machinegun possession or transfer).

One post-Apel and Abramski Circuit decision applies the

Chevron framework to a regulation with criminal and civil enforcement provisions. Competitive Enter. Inst. v. U.S. Dep’t of

Transp., 863 F.3d 911, 915 (D.C. Cir. 2017). But only one judge

signed on to that view; one dissented and another wrote separately to explain that he would reach the same result under de

novo review, which made Chevron’s applicability vel non unnecessary to his vote, id. at 921 (Kavanaugh, J., concurring).

9

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With respect, I am not convinced that my colleagues’ reading of Babbitt as the last word on this

topic is correct. See Solid Waste Agency of N. Cook

Cty. v. U.S. Army Corps of Eng’rs, 531 U.S. 159, 174

n.8, 121 S.Ct. 675, 148 L.Ed.2d 576 (2001) (declining,

post-Babbitt, to address relationship between Chevron and agency regulation interpreting statute with

criminal sanction). The Supreme Court’s most recent

decisions indicate, as the ATF and the plaintiffs argue here, Government Br. 36–37; *41 Codrea Opening Br. at 9–11, that Chevron review does not apply

to a statute/rule with criminal sanctions.10 Apel, 571

U.S. at 369, 134 S.Ct. 1144; Abramski, 573 U.S. at

191, 134 S.Ct. 2259. And if Chevron review does not

apply to a statute/rule with criminal sanctions, Chevron cannot apply to a statute/rule with both criminal

and civil sanctions. See Clark v. Martinez, 543 U.S.

371, 380, 125 S.Ct. 716, 160 L.Ed.2d 734 (2005) (a

statute can have only a single meaning and “[t]he

lowest common denominator, as it were, must govern”); Leocal v. Ashcroft, 543 U.S. 1, 11 n.8, 125 S.Ct.

377, 160 L.Ed.2d 271 (2004) (“[W]e must interpret [a]

statute consistently, whether we encounter its application in a criminal or noncriminal context.”). Again,

with respect, the majority may misread Babbitt,

which itself includes language that can allow its hold10 I leave for another day whether the Government can

“waive” Chevron review, as my colleagues view the ATF’s stance

here. Maj. Op. at 21–23; but see Glob. Tel*Link v. FCC, 866 F.3d

397, 417 (D.C. Cir. 2017) (“it would make no sense for this court

to determine whether” agency action “warrant[s] Chevron deference” if the agency “no longer seeks deference”). I view the

ATF’s stance to be that Chevron is inapplicable—period. Government Br. 36–37.

A80

ing to be reconciled with recent Supreme Court decisions:

We have never suggested that the rule of

lenity should provide the standard for reviewing facial challenges to administrative regulations whenever the governing statute authorizes criminal enforcement. Even if there exist

regulations whose interpretations of statutory

criminal penalties provide such inadequate notice of potential liability as to offend the rule of

lenity, the “harm” regulation, which has existed for two decades and gives a fair warning of

its consequences, cannot be one of them.

515 U.S. at 704 n.18, 115 S.Ct. 2407. Footnote 18

suggests, I submit, that a regulation with a criminal

sanction can violate the rule of lenity but concluded

that the regulation at issue, with its longstanding

definition of “harm,” did not do so. Id. My reading allows Babbitt to be harmonized with more recent decisions: Chevron does not apply to a regulation enforced both civilly and criminally unless the regulation gives fair warning sufficient to avoid posing a

rule of lenity problem. The ATF’s interpretation of

“machinegun” gives anything but fair warning—

instead, it does a volte-face of its almost eleven years’

treatment of a non-mechanical bump stock as not

constituting a “machinegun.”

Although I do not dispute that the ATF has been

delegated general rulemaking authority to implement

section 5845(b), inter alia, I am less certain than my

colleagues that we owe deference to the ATF’s interpretation of section 5845(b). “Deference under Chev-

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ron to an agency’s construction of a statute that it

administers is premised on the theory that a statute’s

ambiguity constitutes an implicit delegation from

Congress to the agency to fill in the statutory gaps.”

FDA v. Brown & Williamson Tobacco Corp., 529 U.S.

120, 159, 120 S.Ct. 1291, 146 L.Ed.2d 121 (2000).

Statutory ambiguity, if it exists, does not necessarily

constitute an implicit delegation. King v. Burwell, ––

– U.S. ––––, 135 S.Ct. 2480, 2488–89, 192 L.Ed.2d

483 (2015); United States Telecom Ass’n v. FCC, 855

F.3d 381, 419–24 (D.C. Cir. 2017) (Kavanaugh, J.,

dissenting from denial of rehearing en banc). The

Congress must, for instance, “speak clearly if it wishes to assign to an agency decisions of vast economic

and political significance.” Util. Air Regulatory Grp.

v. EPA, 573 U.S. 302, 324, 134 S.Ct. 2427, 189

L.Ed.2d 372 (2014) (quotation marks omitted). There

is good reason to believe that a similar clearstatement rule *42 applies in the criminal law context. Under longstanding separation-of-powers principles, the Congress defines the criminal law and

must speak distinctly to delegate its responsibility.11

United States v. Bass, 404 U.S. 336, 348, 92 S.Ct.

515, 30 L.Ed.2d 488 (1971); United States v. Grimaud, 220 U.S. 506, 519, 522, 31 S.Ct. 480, 55 L.Ed.

563 (1911); United States v. Eaton, 144 U.S. 677, 688,

11 The Supreme Court has upheld executive branch interpretations of the criminal law based on express delegations of interpretive authority. See United States v. O’Hagan, 521 U.S. 642,

667, 117 S.Ct. 2199, 138 L.Ed.2d 724 (1997) (Securities Exchange Act of 1934); Touby v. United States, 500 U.S. 160, 165–

69, 111 S.Ct. 1752, 114 L.Ed.2d 219 (1991) (Controlled Substances Act).

A82

12 S.Ct. 764, 36 L.Ed. 591 (1892). Unlike with civil

statutes, then, ambiguity in the criminal law is presumptively for the Congress—not the ATF—to resolve. Whitman v. United States, ––– U.S. ––––, 135

S.Ct. 352, 354, 190 L.Ed.2d 381 (2014) (Scalia, J.,

statement respecting denial of certiorari) (“Congress

cannot, through ambiguity, effectively leave that

function to the courts—much less to the administrative bureaucracy.”). Accordingly, I would treat an

ambiguous criminal statute to be of “vast economic

and political significance” and apply Chevron only if

the Congress expressly delegates its lawmaking responsibility. See Util. Air Regulatory Grp., 573 U.S.

at 324, 134 S.Ct. 2427. The Congress has made no

such clear statement; instead the ATF relies solely on

its general rulemaking power and statutory ambiguity. 18 U.S.C. § 926(a); 26 U.S.C. §§ 7801(a)(2)(A),

7805(a). Chevron is inapplicable. See King, 135 S.Ct.

at 2489.

I believe the applicable standard of review is de

novo and therefore we should go “the old-fashioned”

route and “decide for ourselves the best reading” of

“machinegun.” Miller v. Clinton, 687 F.3d 1332, 1342

(D.C. Cir. 2012) (quoting Landmark Legal Found. v.

IRS, 267 F.3d 1132, 1136 (D.C. Cir. 2001) ). As is always the case in construing a statute, the inquiry focuses on “the plain meaning of the text, looking to the

‘language itself, the specific context in which that

language is used, and the broader context of the statute as a whole.’ ” Blackman v. District of Columbia,

456 F.3d 167, 176 (D.C. Cir. 2006) (quoting United

States v. Barnes, 295 F.3d 1354, 1359 (D.C. Cir. 2002)

). The Bump Stock Rule declares that any bump stock

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device qualifies as a “machinegun.” Although the

Rule—in my view—correctly interprets “single function of the trigger,” it misreads “automatically.”

Moreover, it misapplies its interpretation of “single

function of the trigger” to bump stock type devices.

B. “Single Function of the Trigger”

The Rule determines that “single function of the

trigger” within the statutory definition of “machinegun” means “single pull of the trigger and analogous motions.” Bump-Stock-Type Devices, 83 Fed.

Reg. at 66,554. To me, the “function” of the trigger

means “action” of the trigger. Webster’s New International Dictionary 1019 (2d ed. 1934). According to the

section 5845(b) definition, the trigger function

“shoots” the firearm. 26 U.S.C. § 5845(b) (“The term

‘machinegun’ means any weapon which shoots ... automatically more than one shot, without manual reloading, by a single function of the trigger.”); see also

Fortier v. Olin Corp., 840 F.2d 98, 101 (1st Cir. 1988)

(discussing mechanics of lever-action rifle). “Pull of

the trigger,” then, describes how the trigger works.

See Staples, 511 U.S. at 602 n.1, 114 S.Ct. 1793;

United States v. Camp, 343 F.3d 743, 745 (5th Cir.

2003) (using trigger “pull” and “function” interchangeably); United States v. Oakes, 564 F.2d 384,

388 (10th Cir. 1977) (same). *43 The Rule recognizes

that not all firearms feature a pull trigger; some involve “fire initiated by voice command, electronic

switch, swipe on a touchscreen or pad, or any conceivable number of interfaces.” Bump-Stock-Type Devices, 83 Fed. Reg. at 66,534; see also United States v.

Fleischli, 305 F.3d 643, 655–56 (7th Cir. 2002)

(minigun fired by “electronic switch” is machinegun).

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To include these non-pull methods used to shoot a

firearm, the Rule includes the phrase “and analogous

motions.” Bump-Stock-Type Devices, 83 Fed. Reg. at

66,553.

The plaintiffs claim that the Rule’s interpretation

of “single function” impermissibly shifts the statutory

focus from the trigger’s action to the trigger finger’s

action. But the Rule defines “single function” to mean

“single pull of the trigger and analogous motions.”

The Rule’s definition describes the “motion” of the

trigger, not of the trigger finger. Id. at 66,554. Indeed, nothing in the Rule’s definition refers to a

shooter’s finger or a volitional action. Id. The plaintiffs challenge the Rule because the ATF determines

therein that a bump stock device allows the firearm

to shoot more than one shot with only a single pull.

But that is a question of application, not definition.

As for the definition, I believe the Rule correctly

reads “function” by focusing on how the trigger acts—

that is, through a pull.

C. “Automatically”

The Bump Stock Rule defines “automatically” to

mean “as the result of a self-acting or self-regulating

mechanism that allows the firing of multiple rounds

through a single pull of the trigger.” Id. at 66,519.

The plaintiffs challenge this definition because it

does not account for the additional physical input the

shooter must provide in the firing sequence to make a

firearm with a bump stock shoot more rapidly. That

“pull plus” action, they say, invalidly expands the

statutory text: a “ ‘single function of the trigger’ is the

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starting and the ending point of [making] a firearm

automatic.” Codrea Br. at 14. I agree.12

The Rule’s fatal flaw comes from its “adding to”

the statutory language in a way that is—at least to

me—plainly ultra vires. 1A Sutherland Statutory

Construction § 31.02, at 521 (4th ed. 1985) (“The legislative act is the charter of the administrative agency and administrative action beyond the authority

conferred by the statute is ultra vires.”); see Burnet v.

Marston, 57 F.2d 611, 612 (D.C. Cir. 1932) (“While

the [agency] was clothed with authority to promulgate regulations, [it] was not authorized to add to or

take from the plain language of the statute, for,

‘where the intent is plain, nothing is left to construction.’ ” (quoting United States v. Fisher, 6 U.S. (2

Cranch) 358, 386, 2 L.Ed. 304 (1805))). “Automatically” cannot be read in isolation. On the contrary, it is

modified—that is, limited—by the clause “by a single

function of the trigger.” 26 U.S.C. § 5845(b); Webster’s New International Dictionary 307 (2d ed. 1934)

(defining “by” as “through the means of”). Section

5845(b)’s awkward syntax does not equal ambiguity,

12 A portion of the Bump Stock Rule’s definition of “automatically” strikes me as unobjectionable. It adopts the phrase “functioning as the result of a self-acting or self-regulating mechanism” as a substitute for “automatically.” Bump-Stock-Type Devices, 83 Fed Reg. at 66,554. It does so because dictionaries in

use at the time the 1934 Act was enacted defined “automatically” that way. Id. at 66,519; see also Webster’s New International

Dictionary 187 (2d ed. 1934) (“automatic” means “[h]aving a

self-acting or self-regulating mechanism that performs a required act at a predetermined point in an operation”).

A86

as illustrated by the lost *44 art of diagramming.13

“Automatically ... by a single function of the trigger”

is the sum total of the action necessary to constitute a

firearm a “machinegun.” 26 U.S.C. § 5845(b). A “machinegun,” then, is a firearm that shoots more than

one round by a single trigger pull without manual reloading.14 The statutory definition of “machinegun”

13

Section

5845(b)

can

be

diagrammed

as

fol-

lows:

See

generally Marye Hefty et al., Sentence Diagramming 7–11, 17–

20, 24–25, 30–31, 33, 49 (2008).

14 In United States v. Olofson, 563 F.3d 652 (7th Cir. 2009),

the Seventh Circuit discussed the meaning of “machinegun.” It

explained that “ ‘automatically’ is the adverbial form of ‘automatic,’ ” meaning “[h]aving a self-acting or self-regulating

mechanism.” Id. at 658 (alteration in original) (quoting Webster’s New International Dictionary 187 (2d ed. 1934)). It then

read section 5845(b)’s “automatically” as follows: “the adverb

‘automatically,’ as it modifies the verb ‘shoots,’ delineates how

the discharge of multiple rounds from a weapon occurs: as the

result of a self-acting mechanism.” Id. My rejection of the Bump

Stock Rule creates no tension with Olofson. That court did not

consider whether additional manual input from the nonshooting hand—“pull plus”—takes a device outside section

5845(b)’s definition of “automatically.” Nor did Olofson consider

whether “pull” refers to how the trigger works or to the movement of the shooter’s trigger finger.

A87

does not include a firearm that shoots more than one

round “automatically” by a single pull of the trigger

AND THEN SOME (that is, by “constant forward

pressure with the non-trigger hand”). Bump-StockType Devices, 83 Fed. Reg. at 66,532. By including

more action than a single trigger pull, the Rule invalidly expands section 5845(b), as the ATF itself recognized in the rulemaking. See id. (shooter “maintain[s]

constant forward pressure with the non-trigger hand

on the barrel-shroud or fore-grip of the rifle,” and

“maintain[s] the trigger finger on the device’s extension ledge with constant rearward pressure.”).

My reading of the statute comports with the common sense meaning of the language used. Suppose an

advertisement declares that a device performs a task

“automatically by a push of a button.” I would understand the phrase to mean pushing the button activates whatever function the device performs. It would

come as a surprise, I submit, if the device does not

operate until the button is pushed and some other action is taken—a pedal pressed, a dial turned and so

on. Although the device might be “automatic” under

some definition, it would not fit the advertised definition of “automatic”: by a push of a button period.

More importantly, my reading of the statute—

unlike the ATF’s reading—maintains the longstanding distinction between *45 “automatic” and “semiautomatic” in the firearms context. The original definition of “machinegun” in the 1934 Act included a

firearm that shoots more than one round “automatically or semiautomatically.” 26 U.S.C. § 2733(b)

(1940). At the time, an “automatic gun” was understood to be “[a] firearm which, after the first round is

A88

exploded, by gas pressure or force of recoil automatically extracts and ejects the empty case, loads another round into the chamber, fires, and repeats the

above cycle, until the ammunition in the feeding

mechanism is exhausted, or pressure on the trigger is

released.” Webster’s New International Dictionary

187 (2d ed. 1934). A “semiautomatic gun” was (and is)

“[a] firearm in which part, but not all, of the operations involved in loading and firing are performed automatically, as when the recoil is used to open the

breech and thus prepare for reloading by hand.”

Webster’s New International Dictionary 187 (2d ed.

1934). At the time of the 1934 Act’s enactment, then,

the difference between an “automatic” and a “semiautomatic” gun depended on whether the shooter played

a manual role in the loading and firing process. My

interpretation fits the historical context by limiting

“automatic[ ]” to a firearm that shoots more than one

round by a single trigger pull with no additional action by the shooter. By contrast, the Bump Stock

Rule reinterprets “automatically” to mean what “semiautomatically” did in 1934—a pull of the trigger

plus. The Congress deleted “semiautomatically” from

the statute in 1968 and the ATF is without authority

to resurrect it by regulation.

The ATF insists that my interpretation renders

“automatically” superfluous—a result inconsistent

with the well-established principle that “ ‘[a] statute

should be construed so that effect is given to all its

provisions, so that no part will be inoperative or superfluous, void or insignificant.’ ” Corley v. United

States, 556 U.S. 303, 314, 129 S.Ct. 1558, 173

L.Ed.2d 443 (2009) (alteration in original) (quoting

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Hibbs v. Winn, 542 U.S. 88, 101, 124 S.Ct. 2276, 159

L.Ed.2d

172

(2004)

).

Not

even

close.

“[A]utomatically” means that the firearm shoots more

than one shot as the result of a self-acting mechanism effected by a single pull of the trigger. Thus, the

combination of “automatically” and “by a single pull”

explains how the shooter accomplishes the firing sequence of a “machinegun.” Under my reading, “automatically” excludes a “machinegun” that uses a selfacting firing sequence effected by action in addition

to a single pull of the trigger.

Finally, the ATF, as well as the district court, posits that the Bump Stock Rule meets one ordinary

meaning of “automatically”—that is, “perform[s]

parts of the work formerly or usually done by hand.”

Webster’s New International Dictionary 187 (2d ed.

1934). Both believe that a bump stock “makes it easier to bump fire because it controls the distance the

firearm recoils and ensures that the firearm moves

linearly—two tasks the shooter would ordinarily have

to perform manually.” Guedes, 356 F.Supp.3d at 132.

Maybe so. But the Rule does not use the “formerly

done by hand” meaning of “automatically.” BumpStock-Type Devices, 83 Fed. Reg. at 66,519. It defines

“automatically” to mean “as the result of a self-acting

or self-regulating mechanism.” Id. Whether that definition is consistent with section 5845(b)’s definition is

the question before us.15

15 I am not quibbling about semantics. The two definitions of

“automatically” have different aims: one refers to a self-acting

object; the other refers to automating a formerly “by-hand” task.

Webster’s Third New International Dictionary 148 (1993). The

“formerly by-hand” definition would shift the focus from wheth-

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*46 D. Is a Bump Stock a “Machinegun?”

Having interpreted “automatically” and “single

function of the trigger,” the Rule declares that a “

‘machinegun’ includes a bump-stock-type device, i.e.,

a device that allows a semiautomatic firearm to shoot

more than one shot with a single pull of the trigger

by harnessing the recoil energy of the semiautomatic

firearm to which it is affixed so that the trigger resets

and continues firing without additional physical manipulation of the trigger by the shooter.” Id. at

66,553–54. There are at least two defects in this classification. It ignores the fact that a non-mechanical

bump stock—a type of bump stock device covered by

the Rule—does not allow the firearm to shoot more

rapidly with a single pull of the trigger because the

shooter must provide “constant forward pressure

with the non-trigger hand” for the device to function.

Id. at 66,532. It also erroneously determines that a

bump stock allows a semiautomatic rifle to fire more

than one round with a single pull of the trigger. For

these reasons, I agree with the plaintiffs that a bump

stock is not a “machinegun.”

First, a firearm equipped with a non-mechanical

bump stock does not fire “automatically” because the

shooter must also provide constant forward pressure

with his non-shooting hand. The Rule’s very description of a non-mechanical bump stock manifests that

its proscription is ultra vires:

er a bump stock provides a self-acting mechanism to fire multiple rounds to whether a bump stock automates any action in the

firing sequence.

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[Bump stock] devices replace a rifle’s standard stock and free the weapon to slide back

and forth rapidly, harnessing the energy from

the firearm’s recoil either through a mechanism like an internal spring or in conjunction

with the shooter’s maintenance of pressure

(typically constant forward pressure with the

non-trigger hand on the barrel-shroud or foregrip of the rifle, and constant rearward pressure on the device’s extension ledge with the

shooter’s trigger finger).

Id. at 66,516 (emphases added). This description covers two types of bump stocks, one that includes a

mechanism like an internal spring and the other that

requires the shooter to maintain pressure with his

non-trigger hand. Id. The first type, including the

original Akins Accelerator, has been classified as a

“machinegun” and hence illegal since 2006. Id. at

66,517. The Rule must—and does—aim at the second

type—the non-mechanical bump stock—which operates only in conjunction with the shooter’s added

physical pressure.16 But that added physical pressure

is inconsistent with the statutory definition of a “machinegun,” which fires multiple rounds with a selfacting mechanism effected through a single pull of

the trigger simpliciter. In short, the statute uses

“pull” and the Rule—invalidly—uses “pull plus.”

At oral argument, the ATF asserted that the non-trigger

hand’s “additional forward pressure” is part of the “automatic”

firing process. Transcript of Oral Argument 73–74. “Automatic”

means “self-acting or self-regulating.” Bump-Stock-Type Devices,

83 Fed. Reg. at 66,553. The non-trigger hand’s constant forward

pressure requires physical, not automatic, action.

16

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Other parts of the Rule expose the ATF’s error. In

discussing its interpretation of “automatically,” the

ATF gave the following explanation: “[s]o long as the

firearm is capable of producing multiple rounds with

a single pull of the trigger until [1] the trigger finger

is removed, [2] the ammunition supply is exhausted,

or [3] the firearm malfunctions, the firearm shoots

‘automatically’ irrespective of why *47 the firing sequence ultimately ends.” Id. at 66,519. Yet elsewhere

the ATF describes the firing process of a firearm with

a bump stock as follows: “the shooter ‘pulls’ the trigger once and allows the firearm and attached bumpstock-type device to operate until the shooter releases

the trigger finger or the constant forward pressure

with the non-trigger hand.” Id. at 66,532 (emphasis

added). In my view, this assertion is an explicit

recognition that a bump stock device does not continue shooting rounds with a single trigger pull if the

shooter does not maintain “constant forward pressure

with the non-trigger hand.” Id. at 66,532.

Moreover, I find it difficult to ignore the ATF’s repeated earlier determinations that non-mechanical

bump stocks do not initiate an automatic firing sequence. Three ATF determination letters from 2010

to 2013 explained why non-mechanical bump stocks

are not “machineguns”:

[Our] evaluation confirmed that the submitted stock (see enclosed photos) does attach to

the rear of an AR-15 type rifle which has been

fitted with a sliding shoulder-stock type buffer-tube assembly. The stock has no automatically functioning mechanical parts or springs

and performs no automatic mechanical func-

A93

tion when installed. In order to use the installed device, the shooter must apply constant

forward pressure with the non-shooting hand

and constant rearward pressure with the

shooting hand.

Determination Letter signed by John R. Spencer,

Chief, Firearms Tech. Branch, ATF (June 7, 2010),

reprinted at J.A. 278; see also Determination Letter

signed by John R. Spencer, Chief, Firearms Tech.

Branch, ATF (April 2, 2012), reprinted at J.A. at 279–

80; Letter from Richard W. Marianos, Assistant Dir.

Pub. and Governmental Affairs, to Congressman Ed

Perlmutter (April 16, 2013), reprinted at J.A. 281–82.

The Rule does not fairly treat the ATF’s repeated determinations that a non-mechanical bump stock “performs no automatic mechanical function when installed.” J.A. 278. Instead, it rejects its previous reading as based on an incomplete legal definition of “automatically.” Bump-Stock-Type Devices, 83 Fed. Reg.

at 66,521.17 But those determinations made factual

findings that the non-mechanical bump stock operates only if the shooter applies “constant forward

pressure with the non-shooting hand and constant

17 During the rulemaking, the ATF repeatedly declared that

its earlier determinations “did not include extensive legal analysis of the statutory terms ‘automatically’ or ‘single function of

the trigger.’ ” Bump-Stock-Type Devices, 83 Fed. Reg. at 66,516;

see also id. at 66,514, 66,521, 66,528, 66,531. I defy a careful

reader of the rulemaking to find any legal, as opposed to functional, analysis of a bump stock device, much less substantial

legal analysis. Id. at 66,518 (“[P]rior ATF rulings concerning

bump-stock-type devices did not provide substantial or consistent legal analysis regarding the meaning of the term ‘automatically.’ ”).

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rearward pressure with the shooting hand.” Determination Letter signed by John R. Spencer, Chief,

Firearms Tech. Branch, ATF (June 7, 2010). And

those factual findings dictate that a non-mechanical

bump stock is not a “machinegun” under section

5845(b).

Second, a semiautomatic rifle equipped with a

bump stock cannot fire more than one round with a

single function of the trigger. The plaintiffs argue—

and the ATF does not dispute—that the trigger of a

semiautomatic rifle must release the hammer for

each individual discharge. Nor is there any dispute

that a semiautomatic rifle cannot fire again until the

trigger is released, which causes the hammer to reset. The Rule refers to the release of the trigger as a

“separate” function. Bump-Stock-Type Devices, 83

Fed. Reg. at 66,534 *48 (“While semiautomatic firearms [equipped with certain devices] may shoot one

round when the trigger is pulled, the shooter must release the trigger before another round is fired. Even

if this release results in a second shot being fired, it

is as the result of a separate function of the trigger.”).

Once the trigger shoots, it must be released to reset

the hammer and the trigger must be pulled again for

each subsequent shot. Verified Declaration of Richard

(Rick) Vasquez, former Acting Chief of the Firearms

Tech. Branch of ATF, at 4 (with bump stock, “after

the first shot is discharged, the trigger must be released, reset, and pulled completely rearward, before

the subsequent round is discharged”), reprinted at

J.A. 275. Thus, a semiautomatic rifle equipped with a

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bump stock cannot shoot more than one round with a

single pull of the trigger.18

Still, the ATF insists that a bump stock allows a

firearm to shoot multiple shots with a single pull.

Bump-Stock-Type Devices, 83 Fed. Reg. at 66,553–54.

The ATF focuses on whether the shooter must pull

his index finger more than once to fire multiple shots.

Because a bump stock allows the firearm to fire more

than once with a single pull of the index finger, the

ATF concludes that a bump stock is a “machinegun.”

Remember, however, section 5845(b) uses “single

function of the trigger,” not single function of the

shooter’s trigger finger.

If the focus is—as it must be—on the trigger, a

bump stock does not qualify as a “machinegun.” A

semiautomatic rifle shoots a single round per pull of

the trigger and the bump stock changes only how the

pull is accomplished. Without a bump stock, the

shooter pulls the trigger with his finger for each shot.

With a bump stock, however, the shooter—after the

initial pull—maintains backward pressure on the

trigger and puts forward pressure on the barrel with

18 Record evidence supports my point. As discussed earlier,

the record includes a video of a shooter firing a rifle equipped

with a bump stock. The video is in slow motion and focuses on

the trigger. For each shot the rifle fires, the trigger is pulled by

the shooter’s stationary trigger finger. The trigger is then released between each shot. And the trigger is pulled again for the

next shot. This trigger movement confirms that a bump stock

does not allow a rifle to shoot more than one round with only a

single pull of the trigger. Attached as an appendix are photographs, taken from the video, that illustrate the trigger’s movement during the bump stock’s firing sequence.

A96

his non-shooting hand; these manual inputs cause

the rifle to slide and result in the shooter’s stationary

finger pulling the trigger. Bump-Stock-Type Devices,

83 Fed. Reg. at 66,533 (“The constant forward pressure with the non-trigger hand pushes the firearm

forward, again pulling the firearm forward, engaging

the trigger, and firing a second round.”). The bump

stock therefore affects whether the shooter pulls his

trigger finger or keeps it stationary. It does not

change the movement of the trigger itself, which

“must be released, reset, and fully pulled rearward

before [a] subsequent round can be fired.” Verified

Declaration of Richard (Rick) Vasquez, former Acting

Chief of the Firearms Tech. Branch of ATF, at 3–4.

Like countless other Americans, I can think of little legitimate use for a bump stock. That thought,

however, has nothing to do with the legality of the

Bump Stock Rule. For the reasons detailed supra, I

believe the Bump Stock Rule expands the statutory

definition of “machinegun” and is therefore ultra vires. In my view, the plaintiffs are likely to succeed on

the merits of their challenge and I would grant them

preliminary injunctive relief.

Accordingly, I respectfully dissent.

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*49 APPENDIX

Photograph One: Trigger separates from stationary index finger.

Photograph Two: Trigger comes into contact

with stationary index finger.

APPENDIX B

[Excerpts]

83 FR 66514-01, 2018 WL 6738526(F.R.)

RULES and REGULATIONS

DEPARTMENT OF JUSTICE

Bureau of Alcohol, Tobacco, Firearms, and Explosives

27 CFR Parts 447, 478, and 479

[Docket No. 2018R-22F; AG Order No. 4367-2018]

RIN 1140-AA52

Bump-Stock-Type Devices

Wednesday, December 26, 2018

AGENCY: Bureau of Alcohol, Tobacco, Firearms,

and Explosives; Department of Justice.

*66514 ACTION: Final rule.

***

I. Executive Summary

A. Summary of the Regulatory Action

The current regulations at §§ 447.11, 478.11, and

479.11 of title 27, Code of Federal Regulations (CFR),

contain definitions for the term “machinegun.” [FN1]1

1 Regulations implementing the relevant statutes spell the

term “machine gun” rather than “machinegun.” E.g., 27 CFR

(B1)

B2

The definitions used in 27 CFR 478.11 and 479.11

match the statutory definition of “machinegun” in the

National Firearms Act of 1934 (NFA), as amended,

and the Gun Control Act of 1968 (GCA), as amended.

Under the NFA, the term “machinegun” means “any

weapon which shoots, is designed to shoot, or can be

readily restored to shoot, automatically more than

one shot, without manual reloading, by a single function of the trigger.” 26 U.S.C. 5845(b). The term “machinegun” also includes “the frame or receiver of any

such weapon” or any part or combination of parts designed and intended “for use in converting a weapon

into a machinegun,” and “any combination of parts

from which a machinegun can be assembled if such

parts are in the possession or under the control of a

person.” Id. This definition uses the key terms “single

function of the trigger” and “automatically,” but these

terms are not defined in the statutory text.

The definition of “machinegun” in 27 CFR 447.11,

promulgated pursuant to the portion of section 38 of

the Arms Export Control Act (AECA) (22 U.S.C.

2778) delegated to the Attorney General by section

1(n)(ii) of Executive Order 13637 (78 FR 16129), is

similar. Currently, the definition of “machinegun” in

§ 447.11 provides that a “‘machinegun’, ‘machine pistol’, ‘submachinegun’, or ‘automatic rifle’ is a firearm

originally designed to fire, or capable of being fired

fully automatically by a single pull of the trigger.”

478.11, 479.11. For convenience, this notice uses “machinegun”

except when quoting a source to the contrary.

B3

In 2006, ATF concluded that certain bump-stocktype devices qualified as machineguns under the

NFA and GCA. Specifically, ATF concluded that a

device attached to a semiautomatic firearm that uses

an internal spring to harness the force of a firearm’s

recoil so that the firearm shoots more than one shot

with a single pull of the trigger is a machinegun. Between 2008 and 2017, however, ATF also issued classification decisions concluding that other bump-stocktype devices were not machineguns, primarily because the devices did not rely on internal springs or

similar mechanical parts to channel recoil energy.

Decisions issued during that time did not include extensive legal analysis relating to the definition of

“machinegun.” ATF undertook a review of its past

classifications and determined that those conclusions

did not reflect the best interpretation of “machinegun” under the NFA and GCA.

ATF decided to promulgate a rule that would bring

clarity to the definition of “machinegun”—specifically

with respect to the terms “automatically” and “single

function of the trigger,” as those terms are used to define “machinegun.” As an initial step in the process of

promulgating a rule, on December 26, 2017, the Department of Justice (Department) published in the

Federal *66515 Register an advance notice of proposed rulemaking titled “Application of the Definition

of Machinegun to ‘Bump Fire’ Stocks and Other Similar Devices.” 82 FR 60929. Subsequently, on March

29, 2018, the Department published in the Federal

Register a notice of proposed rulemaking (NPRM) titled “Bump-Stock-Type Devices.” 83 FR 13442.

B4

The NPRM proposed to amend the regulations at

27 CFR 447.11, 478.11, and 479.11 to clarify that

bump-stock-type

This text is long and has been trimmed here. Open the source document for the complete record.