SALT LAKE CITY —  A federal appeals court has rejected a Utah gun enthusiast’s attempt to block a Trump administration rule that bans a gun accessory known as a bump stock.

A three-judge panel from the 10th Circuit Court of Appeals in Denver upheld a district court ruling last year that found Clark Aposhian wasn’t likely to win his challenge to a Bureau of Alcohol, Tobacco, Firearms and Explosives rule that classifies bump stocks as machine guns. The court also found that he failed to show that blocking the ban would not hurt the public’s interest.

“Moreover, the public has a strong interest in banning the possession and transfer of machine guns, including bump stocks. The ban supports the safety of the public in general, and the safety of law enforcement officers and first responders,” according to the 2-1 decision.

The ruling agrees with a U.S. District Court judge’s previous denial of Aposhian’s request for a temporary injunction to prevent the rule from taking effect, concluding he isn’t likely to win his lawsuit on its merits. 

“It doesn’t necessarily bode well, but the bigger issue, the main issue is still out there,” said Aposhian, chairman of the Utah Shooting Sports Council. “We’re in this for the long run.”

Aposhian sued the Department of Justice and the ATF, alleging the federal agencies violated the Constitution in prohibiting bump stocks. He contends only Congress should be able to ban the devices.

“I’m not a huge fan of bump stocks. I’m not a fan of them at all. But they just happen to work as a pretty good placeholder for this issue of government overreach,” he said.

Bump stocks, which modify rifles to fire like automatic weapons, came under intense scrutiny after a gunman used them to kill 58 people and wound 500 others at a country music concert in Las Vegas in 2017. He fired more than 1,000 rounds in 11 minutes.

The Trump administration adopted a new federal rule that redefined the devices as “machine guns,” therefore banning them under existing law. The rule directed owners to destroy or surrender their bump stocks to the ATF before it took effect in March 2019 or face criminal penalties.

Aposhian relinquished his bump stock to the ATF last year pending the outcome of his attempt to block the law.

“The court has allowed ATF to take the lawmaking decision away from Congress and create brand new criminal laws in defiance of the proper constitutional order,” said Caleb Kruckenberg, a lawyer with the New Civil Liberties Alliance, which represents Aposhian in the case.

The organization based in Washington, D.C., could seek a rehearing from the full 10th Circuit Court or petition the U.S. Supreme Court to review the case. It said it would continue to challenge the rule in the Utah case and in another one in Texas.

The 10th Circuit decision came two months after the U.S. Supreme Court rejected an appeal of the ban.

The law defines a machine gun as one that fires more than one shot automatically by a single function of the trigger. A bump stock uses the recoil energy after a shot is fired to keep a gun firing by rapidly bumping the trigger against the shooter’s finger.

In a dissenting opinion, Judge Joel Carson concluded that a semiautomatic weapon equipped with a bump stock isn’t a machine gun under federal law.

To be considered a machine gun the trigger must function only once to fire more than one shot, and the mechanism that allows the trigger to function must be self-acting or self-regulating, he wrote.

“So does a bump stock increase the speed by which the user can fire rounds? Yes,” Carson wrote. “But does that mean the firearm to which it is attached is a machine gun under the National Firearms Act? No.”