Opponents of the bump stock ban were dealt another setback in court on Tuesday.

A three-judge panel for the Fifth Circuit Court of Appeals rejected a challenge to the 2019 rule banning the sale or possession of bump stocks. In its ruling, the court found that the ATF correctly classified bump stocks as machine guns under the National Firearms Act.

“After a trial, the district court rejected Cargill’s claims, concluding in a 75-page order that the Rule ‘properly classifies a bump stock as a ‘machinegun’ within the statutory definition,’” the court wrote. “Because we agree with the district court that bump stocks qualify as machine guns under the best interpretation of the statute, we AFFIRM.”

The decision marks the third Federal Appeals Court to uphold the controversial ban. Earlier this month, an evenly divided Sixth Circuit Court of Appeals allowed the ban to remain in place, and a 2020 Tenth Circuit decision upholding the ban is currently awaiting review by Supreme Court.

Bump stocks are devices that attach to semi-automatic firearms and—with the assistance of the weapon’s recoil—allow it to fire more rapidly. It does not make the weapon fully automatic as a unique pull of the trigger is still required to fire each round.

The court, however, deferred to the ATF’s interpretation that construed the definition of machinegun more broadly to encompass bump stocks.

“ATF’s interpretation of the statute is the best interpretation,” the court said. “The phrase ‘single function of the trigger,’ as used in the NFA, means ‘a single pull of the trigger and analogous motions.'”

The New Civil Liberties Alliance (NCLA), a non-partisan civil rights group, represented the plaintiff challenging the ban in this case. The group criticized the court’s decision.

“The panel’s decision conflicts with the views of a significant majority of judges who have examined that issue,” Richard Samp, Senior Litigation Counsel for NCLA, told The Reload.

Tuesday’s ruling was handed down by a panel of judges all appointed by Democratic Presidents, three of only five such judges among the 17 currently active on the Fifth circuit.

Samp said NCLA would be petitioning to have the case reheard before the entire court.

“On behalf of our client, Michael Cargill, NCLA will be filing a petition with the Fifth Circuit, asking that the case be reheard en banc by all 17 judges on the appeals court,” he said.

He said the fact that other appeals courts were willing to hear the case en banc made it likely that the Fifth Circuit would as well.

The ban was enacted at the request of former President Donald Trump (R.) in 2019 following a mass shooting in Las Vegas. It expanded the definitions of machinegun under federal law to include “bump-stock-type devices.”

The rule covered both the sale and possession of existing bump stocks. Individuals who lawfully acquired the accessory before the rule were forced to either surrender their property or face up to 10 years in prison under the National Firearms Act.

Samp said other courts have acknowledged the mechanical differences between bump stocks and the legal definition of machinegun. He said that the group was confident that the full court would be more receptive to that interpretation.

“Among the many judges whose interpretation of the federal statute conflicts with the Court’s is Chief Judge Tymkovich of the Tenth Circuit.” Samp said. “The Court acknowledged that Judge Tymkovich’s opinion ’makes the strongest case’ that a bump stock does not fit within the statutory definition of a ‘machinegun.’ We agree, and we strongly suspect other Fifth Circuit judges may too.”