Garland v. Cargill Revisions: 6/17/24
The Supreme Court struck down the federal ban on bump stocks, ruling 6–3 that these rapid-fire accessories do not legally qualify as 'machineguns' under federal law and that the gun-regulating agency had no authority to ban them by administrative rule.
The decision means bump stocks are once again legal to own unless Congress passes a new law banning them — placing the policy question squarely before lawmakers rather than the executive branch.
How it got here: A federal district court ruled for the ATF after a bench trial; the Fifth Circuit initially affirmed but then reversed en banc; the government asked the Supreme Court to step in and the Court agreed to resolve a split among federal appeals courts.
The Case in Depth
What happened
Bump stocks are plastic accessories that replace a rifle's shoulder stock and allow the gun's recoil to rapidly push the trigger against the shooter's stationary finger, enabling very high rates of fire. After a gunman used bump stocks to kill 58 people and wound more than 500 at a Las Vegas concert in 2017, the federal Bureau of Alcohol, Tobacco, Firearms and Explosives reversed its longstanding position and issued a rule declaring bump stocks to be "machineguns" under federal law — making them illegal to own. Michael Cargill, a Texas gun shop owner, surrendered two bump stocks under protest and then sued to challenge the rule.
The question before the Court
Did the federal government's gun-regulating agency have the power to ban bump stocks — accessories that help shooters fire semiautomatic rifles rapidly — by declaring them "machineguns" under a 1934 federal law?
The Court's answer
No — the Court ruled that bump stocks do not turn a semiautomatic rifle into a "machinegun" as that term is defined in federal law, and so the ATF had no legal authority to ban them by agency rule.
The Court reached this conclusion on two independent grounds. First, even with a bump stock attached, a shooter must release and reset the trigger between every shot — meaning the rifle still fires only one shot per single "function of the trigger," not multiple shots from one trigger movement as the law requires. Second, even if that were debatable, a bump-stock-equipped rifle still does not fire "automatically" in the statutory sense: the shooter must continuously apply forward pressure with the non-trigger hand to maintain fire, which is ongoing manual input beyond what Congress wrote into the definition. Because both requirements of the statutory definition go unmet, the ATF's rule exceeded the agency's lawful authority.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Hundreds of thousands of bump stock owners who surrendered or destroyed their devices under the agency's ban have no legal recourse. Bump stocks are now legal to purchase and own again. The ruling also signals that executive agencies cannot stretch existing federal gun laws to cover new devices — only Congress can expand the definition of a "machinegun."
What changes now
With the ATF's rule invalidated, bump stocks are immediately legal to own again. Owners who previously surrendered or destroyed their bump stocks under the now-void rule have no legal recourse under this decision. Congress retains the power to ban bump stocks through legislation — Justice Alito's concurrence explicitly invited that step. Unless and until Congress acts, the ATF cannot reimpose a ban under the existing statutory definition of "machinegun."
What this does not decide
The ruling decides only that the existing federal definition of "machinegun" does not cover bump stocks — it does not address whether bump stocks should be legal as a matter of policy. Congress can still ban them by statute. The Court also explicitly set aside spring-powered "mechanical bump stocks," which were not at issue, and did not address ATF's authority over other rapid-fire accessories.
Concurrences and dissents
Concurrence — Justice Alito
Justice Alito agreed with the majority's statutory reading but wrote separately to acknowledge the uncomfortable policy result. He said the Congress that passed the 1934 law would likely have seen no meaningful difference between a machinegun and a bump-stock-equipped rifle. But the text is unambiguous, he argued, and courts must follow it. He pointed out that Congress can solve the problem the Las Vegas shooting exposed by amending the statute — and suggested it might already have done so had the ATF not tried to handle the issue through rulemaking.
Dissent — Justice Sotomayor
“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.”The dissent's argument that a bump-stock rifle plainly meets the commonsense and legal definition of a machinegun.
Justice Sotomayor argued that the ordinary meaning of 'single function of the trigger' refers to a single human action that initiates firing — not the internal mechanical reset of the trigger between shots. Under that reading, a bump-stock rifle is a machinegun: one pull of the trigger combined with maintained forward pressure produces continuous automatic fire, just as holding an M16's trigger down does. She accused the majority of fixating on internal gun mechanics while ignoring the shooter's perspective, and warned that the decision creates a readily exploitable loophole that will have deadly consequences.
How the Court got there
The legal reasoning, step by step
- The federal National Firearms Act defines a 'machinegun' as any weapon capable of firing 'automatically more than one shot, without manual reloading, by a single function of the trigger.' The Court treated this statutory text as the controlling yardstick and asked whether a bump-stock-equipped semiautomatic rifle satisfies both the 'single function of the trigger' element and the 'automatically' element.
- The Court analyzed how the trigger assembly of a semiautomatic rifle actually works: firing one shot requires the trigger to be engaged; it must then be released and allowed to reset mechanically before another shot can fire. Each complete engage-release-reset cycle is one 'function of the trigger.' The same cycle happens every time, with or without a bump stock — the bump stock merely speeds up how quickly these separate cycles occur.
- The Court rejected the ATF's argument that a shooter using a bump stock performs only 'a single pull of the trigger' to initiate continuous fire. Because the shooter's moving finger bumps the trigger anew for each shot — whether by actively flexing or by letting the gun slide forward — each shot results from its own separate trigger function. The Court also noted that ATF's own logic was self-defeating: the same reasoning would classify a plain semiautomatic rifle as a machinegun, which ATF concedes is wrong.
- On the 'automatically' requirement, the Court found an additional independent reason to rule against ATF: firing multiple shots with a bump-stock rifle requires more than a single trigger function — the shooter must also maintain precisely calibrated forward pressure with the non-trigger hand throughout firing. That ongoing manual input goes beyond what the statutory definition allows, just as the ATF itself agrees that a pump-action shotgun ('slam-fired' with one finger held on the trigger) is not a machinegun because it too requires extra manual action from the non-trigger hand.
- The Court turned away ATF's fallback argument — the legal principle that courts should avoid reading statutes in ways that make them useless. The Court held that excluding bump stocks from the machinegun definition does not make the law useless; it still covers all traditional machineguns. ATF's own decade-long position that bump stocks were lawful made it especially hard for the agency to claim the statute would be gutted without the rule.
- The Court closed by noting that Congress could have defined 'machinegun' by a weapon's rate of fire — which would have captured bump stocks — but instead wrote a definition keyed to whether a weapon fires multiple shots automatically from a single trigger function. Courts may not rewrite that choice, even when the result seems to create a policy gap.