Bump Stocks ≠ Machineguns

In 2021, the Sixth Circuit, sitting en banc, was evenly split on whether "bump stocks" attached to semiautomatic rifles qualify as machine guns. See Gun Owners of America, Inc. v. Garland, 19 F.4th 890 (6th Cir. 2021) (en banc). In 2023, the question came before the Sixth Circuit again, and a panel decided that the rule of lenity counsels that the answer is "no."

In Hardin v. Bureau of Alcohol, Tobacco, Firearms & Explosives, No. 20-6380 (6th Cir. Apr. 25, 2023), the court examined 18 USC § 922(o)(1), which makes it unlawful to transfer or possess a machinegun, and 26 USC  § 5845(b), the definition of a machinegun in the National Firearms Act.

Ambiguity arises from the fact that § 5845(b) defines machinegun as a weapon that "automatically" fires more than one shot "by a single function of the trigger." Bump stocks "assist rapid fire by 'bumping' the trigger against one's finger (as opposed to one's finger pulling on the trigger), thus allowing the firearm's recoil, plus constant forward pressure by the non-shooting arm, to actuate the trigger." The Sixth Circuit emphasized that courts are all over the place on this question, as "a significant number of reasonable jurists have reached diametrically opposed conclusions as to whether the definition of a machinegun includes a bump stock," and the ATF itself has even had a "flip-flop" on the question.

The Sixth Circuit thus looked to the rule of lenity, and in particular, Fifth Circuit Judge Ho’s concurrence to the en banc Fifth Circuit decision in Cargill v. Garland, 57 F.4th 447 (5th Cir. 2023). That opinion proposed two analogies: (1) designer drugs, which are just as dangerous as unlawful drugs but not automatically banned by the Controlled Substances Act of 1970; and (2) a case about manslaughter on the “high seas” that was not automatically applicably to rivers.

As with those issues, the Sixth Circuit reasoned, although bump stocks might be indistinguishable from automatic weapons for practical purposes, "the relevant statutory scheme does not clearly and unambiguously prohibit bump stocks." So, under the rule of lenity, the bump stock holder wins.

Concurring, Judge Bush said he would go further: In his view, the statute unambiguously does not apply to bump stocks, so there was no need to resort to the rule of lenity. Citing Judge Murphy’s opinion in Gun Owners of America, he argued ATF was never allowed to apply the machine gun ban to bump stocks through agency ruling. He would have found that, under the statute as written, "the addition of a bump stock to a rifle clearly does not make it a machinegun."