Glock switch
A Glock switch or Glock auto-sear is a small device that can be attached to the rear of the slide of a Glock handgun, converting the semi-automatic pistol into a machine pistol capable of fully automatic fire. As a type of auto sear, it functions by applying force to the trigger bar to prevent it from limiting fire to one round of ammunition per trigger pull. This device by itself, regardless if it is installed on a slide or not, is considered by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to be a machine gun, making possession of the device illegal in the United States under most circumstances. Operation
A Glock switch functions by applying force to a semi-automatic pistol's trigger bar to prevent it from limiting fire to one round of ammunition per trigger pull. Normally, in a semiautomatic pistol, after firing the trigger bar catches the firing pin until the trigger is released, but when depressed by the switch it does not catch. A Glock switch thus converts the weapon into a machine pistol capable of automatic fire. The device is roughly the size of a United States quarter, and when installed on the rear of the slide on a Glock pistol (replacing the slide cover plate), adds a selective fire switch; flipping the switch sets the weapon to full automatic mode, which is capable of firing at up to 1,200 rounds per minute. History

A patent () for the Glock auto-sear was filed in 1996 and approved in 1998, with its invention credited to Jorge A. Leon. A handgun with a Glock switch attached fits the definition of a machine gun under United States federal law. The 1986 Firearm Owners Protection Act made new machine guns illegal for civilians to own, banning "possession and transfer of new automatic firearms and parts that fire bullets without stopping once the trigger is depressed", with the exception of machine guns manufactured prior to May 19, 1986. Those caught with a switch-modified handgun can be prosecuted federally. The penalties for possession of an unregistered machine gun in the United States are up to a $250,000 fine and prison sentences of up to 10 years. In 2019, the ATF recovered thousands of the devices which were imported from China. In 2021 and 2022, people have been manufacturing the switch devices with 3D printers. In March 2022, a Vice News investigation learned that the federal prosecutions which involved conversion devices have been rising since 2017. They determined that from 2017 to 2022, advances in low-cost 3D printers and global commerce on the internet have made the devices available for as little as $20 US. In 2022, federal authorities documented a dramatic rise in the prevalence of the Glock switches. See also
Hell-fire trigger
Bump stock
Recoil operation
Slamfire
Gun politics in the United States

References

External links
Video More 'Glock Switches' confiscated in Tennessee
Video Penny-sized 'Glock switch' turns handgun into automatic weapon

Firearm actions
Gun politics in the United States
Firearm components