The US Court of Appeals for the Fifth Circuit Tuesday reheard arguments in a case filed by gun rights activist Micheal Cargillo to challenge a Trump-era ban on bump stocks. Cargill filed a petition for a rehearing en banc in January, arguing that the challenged rule misclassifies a bump stock as machine guns. 

After a 2017 mass shooting in Las Vegas, the Trump administration enacted a rule broadening the definition of machine gun in the Gun Control Act (GCA) and National Firearms Act (NFA) to include bump stocks. Cargill believes that the rule exceeds the Bureau of Alcohol, Tobacco, Firearms and Explosives’ (ATF) definition of a machine gun. The United States District Court for the Western District of Texas and the US Court of Appeals for the Fifth Circuit upheld the ban.

In court Tuesday, Cargill’s attorney argued that bump stocks are not a machine gun because, in order to fire continuous rounds, one has to “pull back on the trigger and push forward on the barrel to fire rapidly” while “a machine gun is a weapon that can fire more than one shot automatically by a single function of the trigger.”

Other federal courts have upheld the ban, and the US Supreme Court has denied the petitions to review the case twice.