Former President Donald Trump faced criticism from gun rights advocates in 2018 after his then-Acting Attorney General Matthew Whitaker announced that bump stocks would be banned.

However, the Supreme Court heard arguments this week over whether that ban should be permitted to stand.

Device helps rifle shooters quickly pull the trigger

According to NBC News, the controversy centers on whether or not bump stocks are automatic weapons for purposes of the National Firearms Act.

Passed in 1934, the law regulates machine guns, short-barreled shotguns, and rifles, requiring that owners register them with the federal government and pay a $200 tax.

The law was later amended in 1986 to ban the registration of new automatic weapons. What's more, the Gun Control Act of 1968 expanded the definition of a "machine gun" to include accessories "for use in converting a weapon" to fully automatic status.

A bump stock is a device that can be attached to a semi-automatic rifle and uses the weapon's recoil to help users pull the trigger more quickly.

Justices divided over machine gun definition

While a bump stock-equipped rifle can only expel a single round with each trigger pull, the Bureau of Alcohol Tobacco and Firearms (ATF) nevertheless maintains that they are machine guns.

As a former bump stock owner, my Second Amendment rights were infringed.

I'm proud to work for @GunOwners where we continued the fight against @ATFHQ to this day—all the way to the Supreme Court with our own case and with an amicus for @michaeldcargill! pic.twitter.com/sdntPPcjJC

— Aidan Johnston (@RealGunLobbyist) February 28, 2024

That claim is disputed by licensed gun dealer Michael Cargill, whose lawyer challenged the notion that using a bump stock met the "single motion" standard which is required for a weapon to be classified as a machine gun.

NBC News noted that while Justice Neil Gorsuch indicated that he could "understand why these items should be made illegal," the Trump appointed expressed skepticism over whether they are covered by current law.

Gorsuch also pointed out that bump stock owners legitimately purchased the items after they had been previously approved for sale by the ATF.

Bump stocks being sold in some states after lower court rulings

In contrast, NBC News recounted how liberal Justice Elena Kagan reacted incredulously to the notion that bump stocks are anything but machine guns, stressing the " torrent of bullets" they allow users to fire.

Jeremiah Cottle is the bump stock's inventor, and he is currently selling the device to residents of Kentucky, Michigan, Ohio, Tennessee, Texas, Louisiana and Mississippi after lower court decisions found their ban to be unlawful.

"I want to see what the Supreme Court does. I'm not putting the cart before the horse," Cottle told NBC News when asked about his plans.