The attachments typically replace the standard stock on a rifle, such as a semiautomatic AR-15–style or AK platform firearm. The devices, invented in the early 2000s, use the power of the weapon ...

Bump-stocks can be fitted to standard semi-automatic rifles like the Colt AR-15 Police say that the gunman who killed almost 60 people at a concert in Las Vegas had outfitted a legal but ...