Supreme Court is hearing arguments on Trump-era gun bump stock ban. Here’s what to know

The debate around whether or not the federal government can ban “bump stocks” – devices that can be added to a semi-automatic firearm to make a gun fire faster – has now headed to the nation’s highest court.

On Wednesday 28 February, the Supreme Court justices are hearing oral arguments in the case of Garland v Cargill.

The case concerns a ban on bump stocks that the Trump administration imposed after the 2017 Las Vegas mass shooting, where a gunman used a bump stock to fire more than 1,000 rounds of ammunition into a music festival crowd, killing 58 people initially (two other injured individuals died years later) in just 11 minutes.

The ban required the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to prohibit the sale and possession of the devices, claiming it would turn legally obtained semi-automatic firearms into illegal machine guns.

A gun owner and licensed dealer in Texas, Michael Cargill, refuted that when having to surrender his two bump stocks, claiming the ATF overstepped its authority when interpreting a statute on machine guns to include bump stocks.

Unlike other cases involving gun control legislation, this one does not directly challenge the Second Amendment.

Instead, justices will need to decide if the changes a bump stock makes to a semi-automatic firearm effectively turn it into a machine gun – a type of firearm which is currently federally regulated.

Under a 1986 law, machine guns are defined as “any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger”.

That definition also includes a provision for “any part designed and intended, for use in converting a weapon into a machinegun” that can be combined and assembled by a person.

A bump stock meanwhile is defined as a device that can convert a semi-automatic firearm so that it fires continuously with a single pull of the trigger. It is installed on the stock of a firearm to take control of the gun’s recoil allowing it to “bump” back and forth via the trigger.

The phrase, “single pull of the trigger”,  is a point of contention in the case.

The government argues bump stocks allow for the gun to fire multiple rounds with just one pull of the trigger which makes it a machine gun. But attorneys for Mr Cargill say that the only way multiple rounds can be fired is by repeatedly hitting the trigger.

Lower courts, including the ultra-conservative Fifth Circuit of Appeals, have ruled that the bump stock ban was unlawful however the government maintains it was correctly interpreted.

Should the court side with Mr Cargill, the decision will further expand access to firearm attachments that make semi-automatic guns more dangerous. However, a handful of states have individual laws against bump stocks and others may be inspired to adopt similar ones if the nation’s highest court rules against the federal government.

The Supreme Court has mostly expanded gun rights when taking on challenges to the Second Amendment. But since this case is about the ATF’s interpretation of a statute and its authority, justices could be more inclined to side with the government.

A decision in the case is expected before or in June.