bump stocks

In this file photo, a device called a "bump stock" is attached to a semi-automatic rifle at the Gun Vault store and shooting range in South Jordan, Utah.
Rick Rowmer / AP Photo

As a nationwide ban took effect this week, gun owners must immediately destroy or turn over their bump stocks after President Trump pushed the Justice Department to classify the controversial gun add-on as a type of illegal machine gun.

The gun accessory attaches to the butt of a semi-automatic rifle, allowing the weapon to reload and fire more rapidly.

The device became a focal point in the country's debate about gun violence in the months after law enforcement officials said a shooter used one to kill 58 people in Las Vegas in October 2017.