In a 6-3 decision authored by Justice Clarence Thomas, the Supreme Court ruled that a semiautomatic rifle with a bump stock is not a "machinegun" under federal law. Justice Sonia Sotomayor and two other liberal justices dissented. The ruling stated that such a rifle does not fire multiple shots with a single trigger pull. The ATF rule banning bump stocks was implemented after the 2017 Las Vegas music festival shooting, where 58 people were killed and over 850 wounded.

The Supreme Court on Friday struck down a Trump-era ban on bump stocks, a gun accessory that allows semi-automatic weapons to fire rapidly like machine guns and was used in the deadliest mass shooting in modern U.S. history.

“We conclude that semiautomatic rifle equipped with a bump stock is not a ‘machinegun’ [sic],” Justice Clarence Thomas wrote for the majority, “because it does not fire more than one shot ‘by a single function of the trigger.' “Even if a semiautomatic rifle with a bump stock could fire more than one shot ‘by a single function of the trigger,'” Thomas went on, “it would not do so ‘automatically.'”