An Austin gun shop owner succeeded Friday on a years-long quest to overturn a federal ban on bump stocks, winning a 6-3 victory from the U.S. Supreme Court.

Bump stocks are devices that allow semi-automatic rifles to fire hundreds of rounds in a minute. The court ruled the federal Bureau of Alcohol, Tobacco, Firearms and Explosives can not include bump stocks under legislation banning machine guns. The overturned ATF rule required owners of bump stocks to either destroy them or surrender them to the ATF to avoid criminal prosecution.

The U.S. Supreme Court on Thursday ruled that a bump stock does not transform a firearm into an automatic weapon, striking down a federal rule that banned bump stocks. 

In a 6-3 decision, Justice Clarence Thomas wrote, "Congress has long restricted access to "'machinegun[s],'" a category of firearms defined by the ability to "shoot, automatically more than one shot . . . by a single function of the trigger." 

The Supreme Court on Friday overturned a Trump-era ban on bump stocks, ruling that the Bureau of Alcohol, Tobacco, Firearms and Explosives exceeded its authority by determining that the gun attachments turn firearms into machine guns.

The case was decided 6-3, with Justice Clarence Thomas writing the majority opinion and Justice Samuel Alito concurring. Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson, the courts three liberals, dissented.

What are bump stocks?