This story was originally published by the WND News Center.

Bump stocks are attachments that use the ordinary recoil of a firearm to increase the speed at which it can fire.

Critics say that makes them "machine guns," which are banned under federal law except for very rare circumstances.

At least three times already the Supreme Court passed on an opportunity to rule exactly what they are, and how they should be treated.

That's changing. Arguments are scheduled in the coming weeks on a case over those tools.

A report from The Center Square notes the case, Garland v. Cargill, resulted when the Trump administration issued a ban on the devices, and gun rights organizations sued.

It's taken since 2018 for the case to move from its filing date to the high court.

At the time, a new rule from the Bureau of Alcohol, Tobacco, Firearms, and Explosives, was announced following a mass shooting in Las Vegas where nearly 60 were killed, and an investigation showed the killer was using a bump stock device.

The original regulatory plan was for owners to give them to the ATF, or destroy them.

"Specifically, these devices convert an otherwise semiautomatic firearm into a machinegun by functioning as a self-acting or self-regulating mechanism that harnesses the recoil energy of the semiautomatic firearm in a manner that allows the trigger to reset and continue firing without additional physical manipulation of the trigger by the shooter,” the DOJ said. "Hence, a semiautomatic firearm to which a bump-stock-type device is attached is able to produce automatic fire with a single pull of the trigger."

That plan, however, ran into opposition from those who said the government simply was redefining words in its rules to change the intent and impact.