What Is a Bump Stock and How Was It Used in the Las Vegas Shooting?
“The classification of these devices depends on whether they mechanically alter the function of the firearm to fire fully automatic,” Jill Snyder, a special agent in charge at the Bureau of Alcohol, Tobacco, Firearms
and Explosives, said at a news conference in Las Vegas on Tuesday.
“Bump-fire stocks, while simulating automatic fire, do not actually alter the
firearm to fire automatically, making them legal under current federal law.”
Analysis of video posted on social media suggests that the gunman used rifles with rapid-fire capabilities.
The bump stock is not banned under federal law even though it allows a weapon to fire at nearly
the rate of a machine gun without technically converting it to a fully automatic firearm.
Twelve of the rifles the gunman in the Las Vegas mass shooting had in his 32nd-floor hotel room were
each modified with a “bump stock,” an attachment that enables a semiautomatic rifle to fire faster.
(It is illegal for private citizens to possess fully automatic firearms manufactured
after May 19, 1986; ownership of earlier models requires a federal license.)
The stock “bumps” back and forth between the shooter’s shoulder and trigger finger, causing the rifle to rapidly fire again and again.
