Bump-Fires and Similar Devices

Bump-fire devices are just one type of a variety of attachments sold in the United States to increase the rate of fire of semiautomatic firearms to mimic the firepower of a fully automatic machine gun. Many of these devices were not affected by regulations which took effect in 2019 limiting the availability of bump-fires. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is in charge of reviewing such devices to determine whether they enable a firearm to actually function as a machine gun−in which case they are illegal to possess pursuant to the federal ban on the possession by private citizens of machine guns manufactured after May 19, 1986. Following legal challenges to the ban, in November 2023 the U.S. Supreme Court agreed to decide on the legality of the ban.


ATF Opinion Letters on Devices to Increase the Rate of Fire of Semiautomatic Firearms

Below are letters from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) on the legality of various bump-fire and other devices designed to enable semiautomatic firearms to mimic fully-automatic machine gun fire.