Bump Stock Ban Brings Agency Power Dispute to Supreme Court

Guns are back before the US Supreme Court but it’s not a fight over Second Amendment rights.

The case being argued Wednesday involves the reach of a federal statute that bans machine guns and asks if bump stock attachments qualify under the law’s definition.

The dispute is closely watched for its potential to limit the federal government’s ability to interpret ambiguous laws and put a device that was used in the deadliest mass shooting in the US back on the market nationwide.

This case isn’t about whether or not the right to keep and bear arms includes bump stocks, said Eric Ruben, an associate professor at the Southern Methodist University Dedman School of Law.

It’s about whether a bump stock, when applied to a semi-automatic rifle, brings the firearm within the definition of a machine gun that’s banned under the National Firearms Act, he said.

The Trump administration concluded it’s unlawful after one was used by a lone gunman who killed 60 people and wounded 500 others at a 2017 Las Vegas concert.

Who Decides?

Machine guns are defined in the 1986 law as any weapon that operates “automatically” and “by a single function of the trigger.” The court is being asked to decide if the mechanics of a bump stock satisfy those two parts of the definition.

Bump stocks convert a semi-automatic rifle into a machine gun by harnessing the recoil energy of the gun’s first shot to create a continuous firing sequence with a single pull of the trigger, the government said. The device allows the gun to slide back and forth so that the trigger automatically re-engages by “bumping” the shooter’s stationary finger.

The US Court of Appeals for the Fifth Circuit struck down the rule from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). It said the law’s definition of a machine gun is ambiguous when applied to bump stocks.

ATF wants to unilaterally redefine the words machine gun to mean something it doesn’t and only Congress can do that, said David Tryon, director of litigation at The Buckeye Institute, which filed a brief urging the court to uphold the Fifth Circuit’s decision.

“In the case of bump stocks, the law did not change, only the ATF’s interpretation of it changed,” he said. “If the ATF can criminalize activity on its own, so can any agency which regulates our day to day conduct and that should not be.”

The dispute is part of a larger trend of cases that have come before the court challenging the power of federal agencies to interpret laws and write regulations.

The justices heard two cases in January that seek to overturn Chevron deference, a legal doctrine that tells courts to defer to an agency’s reasonable interpretation when there’s an ambiguous law.

One of those challenges was brought by the New Civil Liberties Alliance, which also initiated the dispute over the bump stock ban. The group, which is tied to powerful sources of conservative funding, filed its initial challenge on behalf of Michael Cargill, who owns Central Texas Gun Works, a gun store in Austin, Texas.

Cargill said NCLA approached him because he outspokenly opposed the bump stock ban on social media and in local media.

“They reached out to me and said ‘Hey, you know, we’re looking for a client,’” he said in an interview with Bloomberg Law. “I said, ‘Well, hey, I’m looking for an attorney’ and it was a match made in heaven.”

Regulatory History

The Fifth Circuit said the federal government wasn’t entitled to Chevron deference in this case because the government didn’t ask for it and that framework doesn’t govern the interpretation of laws that apply to criminal penalties.

ATF’s rule requires bump stock owners to destroy or surrender the device to avoid felony charges for violating the machine gun ban, which is punishable by up to 10 years in prison.

Cargill had two bump stocks he surrendered to ATF in March 2019.

“There are other people out there who lost millions of dollars,” he said. “I only had just a few of them in my possession because we sold all the other ones.”

NCLA told the court that property losses could exceed $100 million if the rule is allowed to stand since ATF estimates there were 520,000 bump stocks sold in the nine-year period that the agency excluded them from the machine gun definition.

The regulatory history could prove to be a problem for the government’s appeal.

“I wonder if that just simply adds to the ambiguity if for 10 years ATF could assert this is not in fact a machine gun or machine gun component,” said Robert Cottrol, a George Washington University law professor who co-authored a book about the legal history of the Second Amendment.

“It makes it suspect,” he said. “I don’t know if it’s unassailable but it’s certainly going to be an issue.”

Gun control advocates say bump stocks weren’t well-known until the Las Vegas shooting.

The government should be allowed to respond to a public health crisis and to new technological developments that try to skirt the machine gun ban, said Billy Clark, senior litigation attorney at the Giffords Law Center to Prevent Gun Violence.

“Unfortunately, we’ve seen a lot of different advancements and one I would point to would be auto sears,” he said.

The device sticks inside a semi-automatic rifle or a handgun to make it fully automatic like a machine gun.

“Those are illegal under the same federal machine gun law but that also in part relies in part on an ATF rule from a while back,” Clark said. A ruling against ATF on bump stocks, “could call into question a lot of different regulations,” he said.

The case is Garland v. Cargill, U.S., No. 22-976, arguments 2/28/24.