What Are Bump Stocks? President Trump Is Seeking To Ban Them

President Donald Trump said Tuesday that he signed a memorandum directing Attorney General Jeff Sessions to propose regulations that would ban some gun accessories, including so-called “bump stocks,” which dramatically increase semi-automatic weapons’ potential rate of fire. “I expect that these critical regulations will be finalized very soon,” said Trump.

Trump’s bump stock announcement comes in the wake of last week’s school shooting in Parkland, Florida, which left 17 people dead.

Trump added that he asked Sessions to investigate the legality of such accessories in the aftermath of last year’s mass shooting in Las Vegas, during which the gunman used a bump stock.

The National Rifle Association (NRA) said in October following the Las Vegas shooting that it believes devices like bump stocks should be “subject to additional regulations.” The organization said Tuesday it cannot comment until it has been able to review a final rule.

“The NRA’s stance on this issue has not changed. Fully-automatic weapons have been heavily regulated since the 1930’s, but banning semi-automatic firearms and accessories has been shown time and again to not prevent criminal activity and simply punishes the law-abiding for the criminal acts of others,” a spokesperson for the NRA wrote in an e-mail to TIME.

Here’s what to know about bump stocks and what they can do.

What are bump stocks?

Bump stocks are cheap and legal accessories that can be installed in semi-automatic weapons, allowing gun owners to fire rapidly without having to pull the trigger for each bullet.

If handled properly, a bump stock could increase the rate of fire from between 45 and 60 rounds per minute to between 400 and 800 rounds per minute, Feinstein said in a news release. It’s typically easy to buy the piece, which can sell for about $50 to $400. But Slide Fire — considered one of the main manufacturers of the bump stock — said on its website this week that it has “decided to temporarily suspend taking new orders in order to provide the best service with those already placed.” Slide Fire did not immediately respond to a request for comment. Authorities have not named the manufacturer of the bump stocks Paddock owned.

The device is still available elsewhere, including on Amazon. It was initially meant to help gun owners who have limited hand mobility, according to the AP.

How do bump stocks work?

Bump stocks are difficult to operate and are unpopular among gun enthusiasts, gun expert Paul Glasco told TIME on Thursday. “Real gun guys don’t use them for anything,” said Glasco, an NRA-certified instructor who stars in a local Louisiana TV show, Legally Armed America.

Bump stocks replace the semi-automatic’s butt stock and pistol grip. They use the recoil of the gun to fire multiple rounds in rapid succession. “It, in essence, bounces off your body,” Glasco said.

But in order to get the gun to fire, a shooter has to simultaneously push the handle grip closest to the barrel forward while pulling the handle grip closest to the body backward. “It’s an unnatural motion to push and pull at the same time,” Glasco said. “It’s like you’re ripping something apart.”

A shooter would have to maintain that motion the entire time, gripping the gun with both hands — not just merely holding it. He would also have to resist the intense recoil, which pushes the torso backward, as well as the heat that radiates from the barrel.

It would be tough to accurately hit a target, even for an advanced marksman, Glasco said. “It’s not as easy as people think it is,” he said. “It’s tiring and very hard to control. Because of the posture of your body, and how you have to hold it to your body, it’s difficult to shoot.”

Inexperienced gun owners might buy a bump stock if they can’t afford or manage to get their hands on a fully automatic weapon, which are expensive and scarce because they are largely illegal. “It’s simply a novelty,” Glasco said, adding that a fully automatic weapon can sell for $50,000 to $100,000. “It’s totally ineffective. I call it a poor man’s machine gun.”

Are bump stocks legal?

Bump stocks are legal in America, as are semiautomatic weapons. Fully automatic weapons, which fire in rapid succession without the need to pull the trigger individually, are illegal under the National Firearms Act. But those registered with the government before 1986 can still be legally bought, owned and sold if the transaction goes through the proper federal channels.

On Wednesday, more than two-dozen Democratic lawmakers moved to ban bump stocks through the bill Feinstein introduced.

Republican Sens. John Cornyn and Ron Johnson are among the few GOP lawmakers considering moving forward with the ban legislation. Cornyn told reporters there’s an “obvious concern” about bump stocks after the Las Vegas shooting, according to the AP.

“I own a lot of guns and as a hunter and sportsman I think that’s our right as Americans, but I don’t understand the use of this bump stock and that’s another reason to have a hearing,” he said.

Johnson added: “I have no problem in banning those.”