A federal appeals court has rejected an interpretation of law offered by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) that bump stock devices should be considered machinegun parts and should, therefore, be banned.
Bump stocks are devices that replace the standard stock of a semiautomatic rifle, resting against the user’s shoulder and incorporating the grip behind the trigger. When the rifle is fired, recoil presses the rifle back, resetting the trigger mechanism. But with forward pressure on the barrel, the bump stock allows the barrel—and trigger—to then “bump” forward, pressing against the trigger finger. This allows the user to fire multiple shots from the semiautomatic rifle in rapid succession.
