*Sean Costigan
I. Introduction
A bump stock is a rifle attachment that drastically increases the rifle’s rate of fire.[1] While the federal regulations regarding bump stocks have changed,[2] the courts disagree as to whether the change is valid.[3] This lack of consensus demands judicial resolution to prevent confusion where criminal liability, including felony convictions, is at stake.
II. What are Bump Stocks?
Bump stocks are designed to increase a rifle’s rate of fire beyond what would be manually possible.[4] A bump stock replaces a rifle’s conventional stock, the part that rests against the user’s shoulder.[5] The bump stock allows the rifle to slide forward and backward when fired and harnesses the energy of the rifle’s recoil along the length of the rifle causing the weapon to rapidly shift back and forth.[6] This back-and-forth motion causes the rifle to bump the user’s trigger finger, allowing the user to reactivate the trigger even though the user only pulls the trigger one time.[7] Where without a bump stock a user would need to pull a trigger each time they wanted to discharge a round, bump stocks allow a user to fire multiple rounds (if not the entire magazine) automatically with a single, long trigger pull.[8]
III. The ATF’s Bump Stock Regulations
The law today makes possession of a machinegun a criminal offense (notwithstanding certain exceptions).[9] The relevant statute defines “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. The term shall include . . . 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.[10]
Initially, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) stated that non-mechanical bump stocks were not considered machineguns or machinegun parts[11] due to these bump stocks relying on the recoil from the rifle to function and requiring the user to apply constant forward pressure on the rifle’s barrel.[12] The ATF changed its stance in 2018[13] after a mass shooting at a music festival in Las Vegas, Nevada.[14] During this incident, the shooter killed dozens of people and injured hundreds more while using multiple rifles equipped with bump stocks.[15] In the aftermath,[16] the ATF issued a Final Rule amending its regulation to include bump stocks in its interpretation of “machinegun” because “such devices allow a shooter of a semiautomatic firearm to initiate a continuous firing cycle with a single pull of the trigger.”[17] Owners of bump stocks had ninety days after the Final Rule was published to either destroy these stocks or surrender them to the ATF to avoid criminal liability.[18]
IV. The Circuit Split
In response to the ATF’s ban on bump stocks, multiple lawsuits arose challenging the new regulation.[19] Multiple cases reached separate federal courts of appeals, with two ruling in favor of the regulation and two ruling against it.[20]
In Guedes v. Bureau of Alcohol, Firearms, Tobacco and Explosives, the Court of Appeals for the D.C. Circuit held that the ATF’s construction of the term machinegun to include bump stocks was the best interpretation of the statute.[21] The court focused heavily on two defining terms: “single function of the trigger” and “automatically.”[22] The court held that “single function of the trigger” simply meant pulling the trigger once[23] and “automatically” meant “the result of a self-acting or self- regulating mechanism that allows the firings of multiple rounds.”[24]
A bump stock allows a user to pull the trigger once, causing the rifle to fire rounds one after another, in a self-acting or self-regulating way so long as the trigger continues to be pulled. Accordingly, the court found that bump stocks fell within the definition of machinegun.[25] The Court of Appeals for the Tenth Circuit also upheld the ATF’s new bump stock rule.[26]
In a more recent case, Hardin v. Bureau of Alcohol, Firearms, Tobacco and Explosives, the Sixth Circuit Court of Appeals reached an opposite conclusion.[27] First, the court found the machinegun definition ambiguous as applied to bump stocks, citing differing judicial rulings on the matter and the ATF’s change of stance regarding bump stocks.[28] Second, it held that the ATF’s construction did not deserve deference from the court due to the potential criminal liability involved.[29] For these reasons, the court believed that the rule of lenity applied.[30] Lenity requires a court to strictly construe a criminal statute.[31] Thus, the court held that “it is not enough to conclude that a criminal statute should cover a particular act. The statute must clearly and unambiguously cover the act.”[32] In other words, the ambiguity and lack of deference to the ATF’s construction required the court to interpret the statute in Hardin’s favor.[33] The Fifth Circuit similarly ruled against the ATF’s new bump stock rule.[34]
V. The Supreme Court’s Need to Rule on the Bump Stock Rule
The contradictory holdings coming from these different circuits open the door to inconsistent rulings on the exact same issue, which means a federal rule could be valid in some parts of the county, but not in others. In light of this circuit split, the Supreme Court granted certiorari under Garland v. Cargill in November 2023, signaling that the Court would definitively rule on the validity of the ATF’s new bump stock rule.[35] The Court’s decision would likely depend on whether it finds the machinegun definition ambiguous as it pertains to bump stocks and the applicability of the Chevron doctrine.[36] Until the Supreme Court announces its decision, these opposing rulings will continue to leave people guessing as to whether or not owning a bump stock is a crime.
*Sean Costigan is a second-year student at the University of Baltimore School of Law and a Staff Editor for Law Review. Prior to law school, Sean served the public at the Social Security Administration for 10 years. He was recently inducted into the Royal Graham Shannonhouse III Honor Society as a Distinguished Scholar. He looks forward to externing at the United States Attorney’s Office in Baltimore, Maryland in the Spring 2024 semester.
Photo Credit: U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.
[1] Larry Buchanan et al., What Is a Bump Stock and How Does It Work?, N.Y. Times (Mar. 28, 2019), https://www.nytimes.com/interactive/2017/10/04/us/bump-stock-las-vegas-gun.html.
[2] Bump-Stock-Type Devices, 83 Fed. Reg. 66, 514 (Dec. 26, 2018) (to be codified at 27 C.F.R. pts. 447–49).
[3] See Guedes v. Bureau of Alcohol, Firearms, Tobacco and Explosives, 45 F.4th 306, 310 (D.C. Cir. 2022); see also Hardin v. Bureau of Alcohol, Firearms, Tobacco and Explosives, 65 F.4th 895, 897 (6th Cir. 2023).
[4] Buchanan, supra note 1.
[5] Id.
[6] Id. Additionally, the user needs to apply forward pressure on the rifle’s barrel with their non-trigger hand and rearward pressure with the hand that is holding the pistol grip. Id.
[7] Id.
[8] Bump-Stock-Type Devices, 83 Fed. Reg. 66,514 (Dec. 26, 2018) (to be codified at 27 C.F.R. pts. 447-49).
[9] 18 U.S.C. § 922(o)(1) However, the statute does not apply to “the United States or any department or agency thereof or a State, or a department, agency, or political subdivision thereof.” § 922(o)(2).
[10] 26 U.S.C. § 5845(b).
[11] Guedes v. Bureau of Alcohol, Firearms, Tobacco and Explosives, 45 F.4th 306, 311 (D.C. Cir. 2022).
[12] Id.
[13] Id.
[14] Elizabeth Chuck, Las Vegas Shooting: 59 Killed and More than 500 Hurt Near Mandalay Bay, NBC News (Oct. 2, 2017, 10:33 PM), https://www.nbcnews.com/storyline/las-vegas-shooting/las-vegas-police-investigating-shooting-mandalay-bay-n806461.
[15] Id.
[16] Bump-Stock-Type Devices, 83 Fed. Reg. 66,514 (Dec. 26, 2018) (to be codified at 27 C.F.R. pts. 447-49).
[17] Id.
[18] Id. at 66, 549.
[19] Guedes v. Bureau of Alcohol, Firearms, Tobacco and Explosives, 45 F.4th 306, 310 (D.C. Cir. 2022); Hardin v. Bureau of Alcohol, Firearms, Tobacco and Explosives, 65 F.4th 895, 897 (6th Cir. 2023); Aposhian v. Barr, 958 F.3d 969, 974 (10th Cir. 2020); Cargill v. Garland, 57 F.4th 447, 451 (5th Cir. 2023).
[20] Guedes, 45 F.4th at 312, 323; Hardin, 65 F.4th at 897; Aposhian, 958 F.3d at 974; Cargill, 57 F.4th at 451.
[21] Guedes, 45 F.4th at 317.
[22] Id. at 314.
[23] Id. at 315.
[24] Id. at 316–17.
[25] Id. at 319.
[26] Aposhian v. Barr, 958 F.3d 969, 988 (10th Cir. 2020).
[27] Hardin v. Bureau of Alcohol, Firearms, Tobacco and Explosives, 65 F.4th 895, 897 (6th Cir. 2023).
[28] Id. at 898.
[29] Id. at 899–901.
[30] Id. at 901.
[31] Id. (citing FCC v. Am. Board. Co., 347 U.S. 284, 296 (1954)).
[32] Id. (quoting Cargill v. Garland, 57 F.4th 447, 473 (5th Cir. 2023) (Ho, J. concurring)) (emphases in original) (internal quotation marks omitted).
[33] Id. at 902.
[34] Cargill, 57 F.4th at 473.
[35] Garland v. Gargill, No. 22-976, 2023 WL 7266996 (U.S. Nov. 3, 2023).
[36] Under the Chevron doctrine, if Congress has not clearly spoken on the issue in question, courts are to defer to an agency’s construction of a statute that agency administers. Chevron, U.S.A. v. Nat. Res. Def. Council, Inc. 467 U.S. 837, 843–44 (1984).
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