Garland v. Cargill Revisions: 6/17/24
The Court struck down a federal rule that banned bump stocks, ruling 6-3 that these rifle accessories do not turn semiautomatic weapons into 'machineguns' under the federal statute — and that the ATF overstepped its authority by saying they do.
The decision restores the legality of bump stocks under existing federal law and makes clear that only an act of Congress, not an agency rule, can ban them.
How it got here: A federal district court ruled for the ATF; the Fifth Circuit initially affirmed but reversed after rehearing the case en banc; the Supreme Court agreed to hear the case to resolve a split among federal appeals courts.
The Case in Depth
What happened
In October 2017, a gunman used semiautomatic rifles equipped with bump stocks to kill 58 people and wound over 500 at an outdoor concert in Las Vegas — the deadliest mass shooting in U.S. history. Bump stocks replace a rifle's standard shoulder piece and harness the weapon's recoil to help the shooter fire at rates approaching those of military-style automatic weapons. Michael Cargill, a gun shop owner in Texas, owned two bump stocks. After the ATF reversed years of consistent guidance and issued a rule classifying bump stocks as illegal machineguns, Cargill surrendered his devices under protest and sued to challenge the rule.
The question before the Court
Did the Bureau of Alcohol, Tobacco, Firearms and Explosives have the authority to classify bump stocks — accessories that allow semiautomatic rifles to fire much faster — as illegal "machineguns" under federal law?
The Court's answer
No — the ATF exceeded its legal authority. The federal statute defines a "machinegun" as a weapon that fires "automatically more than one shot, without manual reloading, by a single function of the trigger." A bump-stock-equipped rifle does not meet that definition for two independent reasons.
First, the rifle still fires only one shot per trigger function. Between every shot, the shooter must release pressure on the trigger and allow it to reset before the next shot fires — making each shot the result of a separate trigger action. The bump stock merely speeds up the time between those separate actions; it does not make a single trigger function produce multiple shots. Second, even if one trigger function could somehow cause multiple shots, the firing still would not happen "automatically," because the shooter must simultaneously maintain exactly the right amount of forward pressure with the nontrigger hand. That ongoing manual input goes beyond what the statute requires, meaning the weapon does not fire purely by a single trigger function on its own.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Bump stocks can once again be legally owned by people who are otherwise permitted to possess semiautomatic rifles. The ATF's 2018 ban — which forced owners to surrender or destroy their devices — is nullified. Anyone who wants to ban bump stocks nationwide must now persuade Congress to pass a new law, a path that has stalled repeatedly since the 2017 Las Vegas shooting.
What changes now
The ATF's 2018 rule is invalidated and bump stocks are once again legal to own for anyone who may lawfully possess a semiautomatic rifle. The case is fully resolved on the merits — there is no remand. Any future federal ban on bump stocks would require Congress to pass new legislation. Bills to that effect have been introduced multiple times since the 2017 Las Vegas shooting but have not become law. Justice Alito's concurrence explicitly calls on Congress to act.
What this does not decide
The ruling does not say bump stocks are safe or good policy — Justice Alito's concurrence openly calls for Congress to ban them. It does not affect the regulation of traditional fully automatic weapons, which remain heavily restricted. It also does not resolve whether other rapid-fire accessories (such as "forced reset triggers") are machineguns under the same statute.
Concurrences and dissents
Concurrence — Justice Alito
Justice Alito agreed with the majority that the statutory text left no other reading, but wrote separately to make clear that the Las Vegas massacre demonstrated bump stocks can be just as lethal as machineguns — strengthening the case for amending the law. He noted that Congress could have already acted had the ATF stuck with its prior interpretation, and called on Congress to act now that the legal situation is unambiguous.
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.”Justice Sotomayor arguing that a bump-stock-equipped rifle plainly meets the ordinary definition of a machinegun.
Justice Sotomayor argued that under the ordinary meaning of 'single function of the trigger' — meaning a single action by the shooter to initiate a firing sequence — a bump-stock-equipped rifle is plainly a machinegun: one pull of the trigger, combined with maintained forward pressure, produces continuous automatic fire, just as with an M16. She contended the majority fixated on a gun's internal mechanics rather than the shooter's action, ignored contemporaneous evidence of what Congress meant in 1934, and created a loophole that makes Congress's machinegun ban readily evadable.
How the Court got there
The legal reasoning, step by step
- The Court began with the statutory text of 26 U.S.C. §5845(b), which defines a 'machinegun' as a weapon that fires 'automatically more than one shot, without manual reloading, by a single function of the trigger.' It focused on two key phrases — 'single function of the trigger' and 'automatically' — holding that bump stocks fail both requirements independently.
- On the first phrase, the Court read 'function of the trigger' to mean the mechanical mode of action by which the trigger activates the firing mechanism. In any semiautomatic rifle — with or without a bump stock — the trigger must be released and physically reset between every shot. That reset is what separates one 'function of the trigger' from the next. Each shot after the first is therefore the product of a new, distinct trigger function, not a continuation of the first.
- The ATF argued that a shooter using a bump stock need only pull the trigger once to start a continuous firing sequence, because the recoil-driven cycle then carries on without the shooter flexing a finger again. The Court rejected this, finding no meaningful legal difference between a shooter pulling the trigger with a finger flex and bumping the trigger with forward pressure — each 'bump' is a separate trigger function. The ATF's own reasoning was also self-contradicting: its logic would equally classify a plain semiautomatic rifle (without any bump stock) as a machinegun, which even the ATF concedes is wrong.
- On the second phrase — 'automatically' — the Court held that firing multiple shots with a bump stock requires more than just a single trigger function; it also demands that the shooter maintain precisely calibrated forward pressure on the rifle's front grip with the nontrigger hand throughout. Too much or too little pressure and the continuous fire stops. That ongoing manual input from the shooter means the weapon does not fire multiple shots automatically — it fires them only because of an additional physical act beyond engaging the trigger.
- The ATF also argued the Court should apply the 'presumption against ineffectiveness' — a legal principle that disfavors readings of a statute that make it easy to evade. The Court rejected this, reasoning that excluding bump stocks from the machinegun definition does not come close to making the statute useless: the law still fully covers all traditional automatic weapons. The fact that Congress could have written the law more broadly — for example, by defining machineguns by rate of fire — does not give agencies or courts license to rewrite the statute Congress actually enacted.