State Legislative Toolkit: Addressing Bump Stocks

Bump stocks and other similar devices are marketed to shooters seeking to convert their weapon to simulate the rapid, continuous fire of an automatic firearm while using a semi-automatic gun. In October 2017, a gunman in Las Vegas used multiple bump stock devices to convert semi-automatic rifles into weapons that fired 9 shots per second. He used those weapons to carry out the deadliest mass shooting attack in modern history. These devices are currently legal in most states and are not regulated by the federal government.

Download State Legislative Toolkit: Addressing Bump Stocks as a PDF. 

Why Are Bump Stock Devices Legal?

For over eight decades, federal law has strictly regulated the sale, manufacture, and possession of machine guns, which are fully automatic firearms that continue to fire bullets as long as the trigger is pressed and ammunition is available. This continuous fire feature makes machine guns particularly lethal if they are in the wrong hands.

Under existing federal law, a person may only transfer, acquire, or own a machine gun that was lawfully manufactured and owned prior to May 19, 1986. The transfer must also be approved by the Bureau of Alcohol, Tobacco, Firearms & Explosives (ATF) subject to a thorough background check, registration, and other requirements as outlined under the National Firearms Act. These restrictions have been highly effective and help explain why fully automatic machine guns are very rarely used in crimes or mass shooting attacks.

In recent years, however, the gun industry has marketed bump-stocks and similar devices, such as trigger cranks, that attach to a semi-automatic firearm and are de...