A simple device that speeds up a semiautomatic weapon’s rate of fire is at the center of a case that could cast a shadow over a government agency’s ability to regulate firearms.
For Michael Cargill, a fierce defender of gun rights who sells firearms in Austin, the accessory, a bump stock, was until 2017 a niche item on the shelves of his store, Central Texas Gun Works. It mainly appealed to people who were injured or disabled, like veterans who needed support firing a gun or by “people who just wanted to have fun,” he said.
But that year, a high-stakes gambler stationed on the 32nd floor of a Las Vegas hotel opened fire on a country music festival, killing 60 people and injuring hundreds. In his arsenal were a dozen AR-15-style rifles outfitted with the device.
Government officials swiftly called for a ban, eliciting alarm among gun store owners like Mr. Cargill, 54, a gregarious Army veteran who said that the mugging and assault of his grandmother had shaped his views on gun control.
“I was one of the only people who said, hold on, wait a minute,” said Mr. Cargill, who has challenged the ban and is represented by the New Civil Liberties Alliance, a legal advocacy group that primarily challenges what it views as unlawful uses of administrative power. “This is insane that anyone would go along with this. We need to stop this now.”
On Wednesday, the Supreme Court will consider whether the Trump administration acted lawfully in enacting a ban that makes it illegal to buy or possess the part. It is not a case that turns on the Second Amendment. Rather, it is one of a number of challenges aimed at limiting the reach of administrative agencies — in this instance, the Bureau of Alcohol, Tobacco, Firearms and Explosives.
“During the Trump administration, the bump stock ban cropped up as a rather glaring example of unlawful administrative power,” Philip Hamburger, a founder of the New Civil Liberties Alliance, said in an email. “This rule turned half a million people into felons overnight. That’s not a power that the Constitution gives to administrative agencies — so it deserved a lawsuit.”
In a brief to the court, the solicitor general, Elizabeth B. Prelogar, arguing for the government, said that reversing the ban “threatens significant harm to public safety.”
“Bump stocks are machine guns because they allow a shooter to fire ‘automatically more than one shot by a single function of the trigger,’” Ms. Prelogar wrote.
The case hinges on whether bump stocks convert semiautomatic rifles into machine guns.
The device hooks onto a rifle’s stock, the part of the gun that is held against the shoulder, and harnesses the energy from the gun’s kickback to bump the stock back and forth, allowing the weapon to fire faster.
The bureau enacted the ban in 2018 by clarifying its interpretation of the National Firearms Act of 1934, which makes it a crime to make or own a machine gun, saying it extended to bump stocks. Under federal law, a machine gun is 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.”
At issue is whether the A.T.F. overstepped its bounds in enacting a ban without congressional action. A ruling against the agency could undermine its authority to regulate firearms and accessories.
The day before the ban went into effect, Mr. Cargill strolled into the A.T.F. office in Austin, handed over two bump stocks and announced his lawsuit.
Mr. Cargill said he hoped gun owners would pay close attention, even though the case does not center on the Second Amendment.
“It doesn’t matter if you’re pro-gun or anti-gun,” he said. “An agency can’t do this.”
The president of the New Civil Liberties Alliance, Mark Chenoweth, said the case fit in with other legal challenges by the group.
“A.T.F. is completely misinterpreting existing law to reach this far-fetched result,” Mr. Chenoweth said in an email, “and it flip-flopped from the interpretation it maintained for over a decade — including during the entirety of the Obama administration.”
Mr. Chenoweth declined to discuss the organization’s donors, but he said that group receives support from “a wide variety of donors.”
“N.C.L.A. is completely independent and not part of any other organization, umbrella group or donor entity,” Mr. Chenoweth wrote.
Federal tax documents show the group has received at least $1 million from the conservative Charles Koch Foundation. Mr. Chenoweth previously served as counsel for legal reform for Koch Industries.
The lead lawyer in the case is Jonathan F. Mitchell, best known for drafting anti-abortion laws that ultimately led the Supreme Court to abolish the constitutional right to the procedure. Mr. Mitchell, who declined to comment, also recently argued on behalf of former President Donald J. Trump to challenge the Colorado Supreme Court’s decision to remove him from the state’s primary ballot.
The lethal potential of a bump stock, which retailed for less than $200 when it first went on the market in 2010, came into startling view in October 2017.
That month, Stephen Paddock, 64, took aim at thousands of concertgoers, firing more than 1,000 rounds of ammunition over about 11 minutes. It remains the deadliest mass shooting in modern U.S. history. Investigators found about a dozen rifles modified with bump stocks in his hotel suite.
The day after, Mr. Cargill’s store sold out of bump stocks.
“Whenever something happens like a shooting incident or something like that and people think the government is going to ban a particular part, people then want to purchase them,” Mr. Cargill said.
Unusual alliances emerged to back a ban on bump stocks, but there were signs from the start that the politically divisive move could be open to challenges.
Lawmakers, including several leading Republicans, signaled openness to prohibiting the device. Even the National Rifle Association endorsed tighter restrictions.
Spurred in part by the mounting political pressure, Mr. Trump, a vocal supporter of the Second Amendment, vowed to enact a ban.
In response, the Justice Department promised to review the legality of bump stocks, but A.T.F. officials had privately indicated that any ban would likely require action by Congress, where bipartisan action has often stalled.
The A.T.F.’s decision to ban the device amounted to an about-face, raising questions about the extent of its authority to regulate the accessory.
Mr. Cargill was among those outraged by the ban, saying it would open the door to more gun control.
“You give the A.T.F. an inch, they will take a mile,” Mr. Cargill said. “I was shocked that no one was putting up a fight. I said, something has got to be done. You can’t just walk into people’s homes and take something that they legally purchased.”
Federal courts wrestled with the legality of the ban, issuing conflicting rulings. The divisions increased the likelihood that the Supreme Court would weigh in.
After a federal trial judge in Texas sided with the government in Mr. Cargill’s case, he appealed to the U.S. Court of Appeals for the Fifth Circuit. Eventually, the full court agreed with Mr. Cargill by a vote of 13 to 3, split along ideological lines.
“A plain reading of the statutory language, paired with close consideration of the mechanics of a semiautomatic firearm, reveals that a bump stock is excluded from the technical definition of ‘machine gun’ set forth in the Gun Control Act and National Firearms Act,” Judge Jennifer Walker Elrod wrote.
Addressing concerns that “bump stocks contribute to firearm deaths,” she added that “it is not our job to determine our nation’s public policy.”
The three dissenting judges, all Democratic appointees, argued that the majority’s reasoning served to “legalize an instrument of mass murder.”
