A bump fire stock that attaches to a semi-automatic rifle to increase the firing rate is seen at Good Guys Gun Shop in Orem
A bump fire stock that attaches to a semi-automatic rifle to increase the firing rate is seen at Good Guys Gun Shop in Orem, Utah, U.S., October 4, 2017. Reuters

A U.S. appeals court on Friday struck down a rule the Trump administration had adopted following a 2017 Las Vegas mass shooting that banned "bump stocks," devices that allow people to rapidly fire multiple rounds from semi-automatic guns.

In a 13-3 decision, the New Orleans-based 5th U.S. Circuit Court of Appeals said that despite "tremendous" public pressure to impose a ban, it was up to the U.S. Congress rather than the president to take action.

While the federal Bureau of Alcohol, Tobacco, Firearms (ATF) and Explosives had interpreted a law banning machineguns as extending to bump stocks, U.S. Circuit Judge Jennifer Walker Elrod said the law did not unambiguously prohibit them.

Elrod, writing for the majority, said the law also did not give "fair warning that possession of a non-mechanical bump stock is a crime."

One of the dissenting judges, Stephen Higginson, wrote that the majority employed reasoning "to legalize an instrument of mass murder."

Three other federal appeals courts have rejected challenges to the ban. While the Supreme Court in October declined to hear appeals from two of the earlier decisions, Friday's ruling raises the prospect the court could eventually decide the issue.

"The resulting circuit split should bring this decision to the U.S. Supreme Court's attention promptly and supply a suitable vehicle for deciding this issue once and for all," said Mark Chenoweth, the president of the New Civil Liberties Alliance, a conservative group that litigated the case.

ATF, the arm of the Justice Department that adopted the rule, declined to comment.

A bump stock lets a gun's stock, which rests against the shoulder, slide backward and forward, letting users take advantage of the gun's recoil to fire rapidly.

Though gun restrictions are often championed by Democrats, former President Donald Trump's Republican administration imposed the ban on bump stocks through an ATF rule after a gunman used them in killing 58 people at an October 2017 country music concert in Las Vegas.

Democratic President Joe Biden's administration also supports the ban, which took effect in 2019.

In December 2021, a three-judge 5th Circuit panel had upheld the ban, ruling against Texas gun owner Michael Cargill, who opposed it.

Friday's decision reversed that ruling. Most of the judges in the majority were appointed by Republican presidents, while the dissenting judges were appointed by Democratic presidents.