The earsplitting roar of fully automatic weapons hasn’t been often heard on U.S. streets since Congress largely outlawed them in 1934. It’s back, owing to a small device that is easily plugged into certain handguns and rifles, converting semiautomatic firearms into guns capable of firing 20 bullets in one second — with one pull of the trigger, reports the Washington Post. In Sacramento last year, a handgun converted into a machine gun was used during a gun battle that left six dead, in the city's deadliest mass shooting. In Minneapolis, eight people were wounded in August amid a spray of 40 bullets fired in seconds. In 2021, a Houston police officer was killed and another wounded by a suspect with a pistol equipped with the device. “It’s incredibly scary,” said U.S. Attorney Matthew Graves, in Washington, D.C. citing the rising number of conversion devices found in the city. There were 27 guns recovered with the devices in 2021. The number rose to 119 last year, and, as of late October, the number was more than 150. Police often find extended magazines attached to the guns, to hold more than the standard 12 or 13 bullets contained in most magazines, and they have even seized round drum magazines, which can hold 50 or more bullets.
“We have no shortage, unfortunately, of crime scenes where we have strong reason to believe, based on the number of rounds expended, that one of these devices was used,” Graves said. The devices have many names: Switch. Giggle switch. Sear. Auto sear. Conversion device. Glock switch (some of which have Glock’s logo fraudulently printed on them). Even though they are small and don’t themselves contain bullets, the devices are considered machine guns by the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, said Craig Kailimai of ATF’s Washington field division. The devices can be made of metal or plastic, and authorities believe some are imported from China and sold on the streets. 3D printers also have been used to make both the square-shaped switch for pistols and an S-shaped device that slides into guns such as the AR-15 to convert them to fully automatic, Kailimai said. The printing process takes about 45 minutes.