What the bump stock ban could mean for guns in the U.S.

The U.S. Supreme Court today overturned a federal ban on bump stocks, the devices that can attach to a semi-automatic rifle to make it fire as fast as a machine gun -- potentially hundreds of rounds a minute.

Machine guns have been effectively banned for most people since the 1930s, but there have been doubts about whether that ban applies to attachments that can make legal guns shoot as fast as a machine gun. The Bureau of Alcohol, Tobacco, Firearms and Explosives determines that, and over the years the agency went back and forth over whether to ban bump stocks. But in 2017, a man using bump stocks committed the deadliest gun massacre in modern American history, killing 60 people and injuring hundreds at a Las Vegas concert. After that mass shooting, many bump stock owners saw a ban coming. The Trump Administration then indeed moved to ban bump stocks, a restriction that took effect in 2019.

What was the court's reasoning to lift that ban?

It all comes down to the law's definition of machine gun, which says it's a gun that fires multiple rounds with "a single function of the trigger." That word "function" is key here, as it's not the same as a pull of the trigger.

With a bump stock, you pull the trigger once, holding it, bracing the stock against your shoulder while the recoil moves the trigger for you very rapidly, firing those rounds at machine-gun speeds; one pull, but multiple trigger functions.

What the court said today is that's a big enough difference that the ATF was wrong to call a bump stock a "machine gun" as defined by the law.

That seems to be a very technical distinction. Could this end up permitting other kinds of gun attachments?

Probably not directly because it's so narrowly focused on the mechanics