A Trump administration ban on bump stocks — devices that enable a shooter to rapidly fire multiple rounds from semi-automatic weapons after an initial trigger pull — was struck down Friday by a federal appeals court in New Orleans.

The ban was instituted after a gunman perched in a high-rise hotel using bump stock-equipped weapons massacred dozens of people in Las Vegas in 2017. Gun rights advocates have challenged it in multiple courts. The 13-3 ruling at the 5th U.S. Circuit Court of appeals is the latest on the issue, which is likely to be decided at the Supreme Court.

The decision doesn’t have an immediate effect on the ban though because the case now moves back to the lower court to decide how to proceed.

The case was somewhat unique because the issue involves not the Second Amendment but the interpretation of federal statutes. Opponents of the ban argued that bump stocks do not fall under the definition of illegal machine guns in federal law. The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives says they do, a position now being defended by the Biden administration.

“A plain reading of the statutory language, paired with close consideration of the mechanics of a semi-automatic firearm, reveals that a bump stock is excluded from the technical definition of ‘machinegun’ set forth in the Gun Control Act and National Firearms Act,” Judge Jennifer Walker Elrod wrote in the lead majority opinion.

The court found that the definition of a machinegun — which is set out in two different federal statutes — “does not apply to bump stocks.”

The ban had survived challenges at the Cincinnati-based 6th U.S. Circuit Court of Appeals; the Denver-based 10th Circuit; and the federal circuit court in Washington. A panel of three judges at the 5th Circuit also issued a ruling in favor of the ban, upholding a lower court decision by a Texas federal judge. But the full New Orleans-based court voted to reconsider the case. Arguments were heard Sept. 13.

Bump stocks harness the recoil energy of a semiautomatic firearm so that a trigger “resets and continues firing without additional physical manipulation of the trigger by the shooter,” according to the ATF. A shooter must maintain constant forward pressure on the weapon with the non-shooting hand, and constant pressure on the trigger with the trigger finger, according to court records.