On June 14, 2024, the U.S. Supreme Court decided Garland v. Cargill, holding that semi-automatic rifles equipped with bump stocks are not “machineguns” under the National Firearms Act of 1934, and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) exceeded its statutory authority by issuing a rule providing that they are.

The Act 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.” 26 U.S.C. § 5845(b). Semi-automatic rifles equipped with bump stocks use the gun’s recoil to help rapidly and repeatedly pull the gun’s trigger. After the 2017 Las Vegas mass shooting, which involved a semi-automatic rifle with a bump stock, ATF issued a rule providing that such firearms qualify as machineguns. A gun owner challenged the rule, and the District Court ruled for ATF. The Fifth Circuit reversed and ruled for the gun owner. 

The Supreme Court held that a semiautomatic rifle equipped with a bump stock is not a “machinegun” under 26 U.S.C. § 5845(b). The Court focused on two portions of the statutory text. First, it held that a semiautomatic rifle equipped with a bump stock cannot fire more than one shot “by a single function of the trigger.” Second, the Court held that even if a semiautomatic rifle equipped with a bump stock could fire more than one shot “by a single function of the trigger,” it could not do so “automatically” because firing multiple shots requires additional actions, including maintaining forward pressure on the rifle’s front grip with the non-trigger hand. Without addressing whether any deference was due to ATF’s interpretation of the Act, the Court affirmed the judgment holding that its rule exceeded its authority.

Justice Thomas delivered the opinion of the Court, in which Chief Justice Roberts and Justices Alito, Gorsuch, Kavanaugh, and Barrett joined. Justice Alito filed a concurring opinion. Justice Sotomayor filed a dissenting opinion in which Justices Kagan and Jackson joined.