The Supreme Court’s big Second Amendment case this term was United States v. Rahimi, 602 U.S. __ (2024), which I wrote about here. But readers interested in firearms law should know that the Court also decided Garland v. Cargill, 602 U.S. 406 (2024), a case addressing the legal status of bump stocks. The case isn’t a criminal case, and it mostly isn’t a Second Amendment case, but it is an interesting case with important implications for administrative law and perhaps for the future of gun regulations.
Bump stocks. A bump stock is a device that can be affixed to the shoulder stock of a semi-automatic rifle. After a shot is fired, the bump stock uses the gun’s recoil to “bump” or bounce the gun back against the shooter’s stationary trigger finger, leading to another shot being fired – and another and another, so long as the shooter holds his or her finger in place and maintains forward pressure on the rifle with his or her non-trigger hand. The New York Times explains the technology, with an illustrative video, here. Bump stocks became widely known in 2017 when Stephen Paddock used them while killing dozens of people and wounding hundreds more at the Harvest Music Festival in Las Vegas.
Pre-2018 legal status. Bump stocks were not illegal under federal law at the time of the Las Vegas shooting. Federal law 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). And it is generally “unlawful for any person to transfer or possess a machinegun.” 18 U.S.C. § 922(o). But “[o]n more than 10 separate occasions over several administrations,” the Bureau of Alcohol, Tobacco, and Firearms (ATF) had taken the position that a semi-automatic rifle equipped with a bump stock was not a “machinegun” because even with a bump stock, the trigger must “function” once per shot. Cargill slip op. at 3.
2018 regulation. In 2018, in response to the Las Vegas shooting, ATF reversed course and issued a new regulation stating that
[t]he term ‘machinegun’ includes a bump-stock-type device, i.e., a device that allows a semi-automatic firearm to shoot more than one shot with a single pull of the trigger by harnessing the recoil energy of the semi-automatic 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. 66514. ATF directed owners of bump stocks to destroy them or to relinquish them to ATF within 90 days.
Legal challenge. Michael Cargill, the owner of Central Texas Gun Works in Austin, Texas, turned in two bump stocks and filed suit against the ATF under the Administrative Procedures Act, alleging that the new rule was inconsistent with the statute it purported to interpret. (This local article features a video of Cargill talking about why he brought the case and celebrating his victory.) Cargill lost in the district court, 502 F. Supp. 3d 1163 (W.D. Tex. 2020), and lost his initial appeal to the Fifth Circuit, 20 F. 4th 1004 (5th Cir. 2021), but prevailed on rehearing en banc, 57 F. 4th 447 (5th Cir. 2023). The Supreme Court granted certiorari.
SCOTUS majority opinion. Cargill prevailed in the Supreme Court as well. Justice Thomas wrote for the six conservative Justices who comprised the majority. In a nutshell, the majority reasoned that
[a] semiautomatic rifle equipped with a bump stock does not fire more than one shot “by a single function of the trigger.” With or without a bump stock, a shooter must release and reset the trigger between every shot. And, any subsequent shot fired after the trigger has been released and reset is the result of a separate and distinct “function of the trigger.” All that a bump stock does is accelerate the rate of fire by causing these distinct “function[s]” of the trigger to occur in rapid succession.
Cargill Slip Op. at 7. Justice Thomas likened a bump stock to a shooter with a “lightning fast trigger finger.” Such a shooter would still be pulling the trigger separately for each shot, just very quickly. And the shooter’s rifle would remain a semiautomatic rifle, not a machinegun. Id. at 12.
Further, ATF apparently conceded that a skilled shooter can bump fire a rifle without a bump stock and acknowledged that such a rifle would not be a machinegun. The majority saw this as “logically inconsistent” with the idea that bump stocks convert semi-automatic rifles into machineguns. Id. at 14.
The majority additionally reasoned that even if a bump stock allowed a rifle to fire more than one shot by a single function of the trigger, it would not do so “automatically” because additional input is required by the shooter. For bump firing to work, the shooter must maintain forward pressure on the rifle with his or her non-trigger hand. This means that to fire more than one shot, the shooter must activate the trigger “and then some,” meaning that activating the trigger does not automatically – but rather, only conditionally – allows the firing of multiple shots. Cargill slip op. at 14-16.
Finally, the majority considered and rejected ATF’s argument that interpreting “machinegun” to exclude bump stocks would violate the presumption that Congress does not enact useless laws. Justice Thomas wrote that excluding bump stocks “comes nowhere close to making [the law] useless” as it “still regulates all traditional machineguns.”
Justice Alito’s concurrence. Justice Alito joined the majority opinion and wrote a brief concurrence noting that “[t]here is a simple remedy for the disparate treatment of bump stocks and machineguns. Congress can amend the law—and perhaps would have done so already if ATF had stuck with its earlier interpretation. Now that the situation is clear, Congress can act.” I think it is a reasonable inference from Justice Alito’s opinion that he does not think that a Congressional ban on bump stocks would violate the Second Amendment, but that issue was not before the Court and he did not address it explicitly.
The dissent. Justice Sotomayor wrote for the three dissenters. She began by noting that “When I see a bird that walks like a duck, swims like a duck, and quacks like a duck, I call that bird a duck.” Cargill slip op. at 2. For the dissent, a bump-stock equipped semiautomatic rifle works like a machine gun and should be treated as one.
Justice Sotomayor describes the case as not being a hard one, and critiques the majority for “a myopic focus on a trigger’s mechanics rather than on how a shooter uses a trigger to initiate fire.” For her, the “function” of a trigger takes place when the shooter presses it to begin shooting, while the back-and-forth bumping of the trigger via a bump stock is just a physically-dictated result of the “function” activated by the shooter. Id. at 7-8.
Comments. As I noted at the outset, Cargill isn’t a Second Amendment case – it’s an administrative law case. Cargill’s argument was that ATF promulgated a regulation that was incompatible with the statute it purported to implement. The Court’s lack of deference to ATF’s interpretation of the statute prefigured the Court’s decision a few weeks later in Loper Bright Enters. v. Raimondo, 603 U.S. __ (2024), in which it overruled a long-standing doctrine (called “Chevron deference”) that required courts to defer to administrative agencies’ interpretations of statutes in debatable cases. Readers interested in a deeper dive into Loper Bright Enterprises and administrative law should check out a forthcoming blog post by my colleagues Kirsten Leloudis and Jim Joyce, which will soon be posted on Coates’ Canons, a School of Government blog on local government law.
Although Cargill wasn’t argued as a Second Amendment case, a Second Amendment issue might still be lurking in the background. If Congress chooses to regulate or prohibit bump stocks, a plaintiff might raise a Second Amendment challenge. It doesn’t sound like Justice Alito thinks that such a challenge would be a strong one, but since none of the other conservative Justices signed on to his concurrence, it is unclear how many of his colleagues would agree.
A final issue relates to state laws. North Carolina doesn’t have a law about bump stocks specifically, but several states do. The Giffords Law Center summarizes those provisions here. After Cargill, more states may choose to address bump stocks given what some may see as a gap in federal law. There has not been much litigation over such state laws. The leading case seems to be Maryland Shall Issue v. Hogan, 353 F.Supp.3d 400 (D. Md. 2018), aff’d 963 F.3d 356 (4th Cir. 2020), which upheld Maryland’s law over claims that it violated due process and the Takings Clause.