A federal appeals court grilled lawyers for California on Wednesday over the state’s law requiring background checks for ammunition purchases as judges weighed whether it violates the Second Amendment.

The full bench of the U.S. Court of Appeals for the Ninth Circuit heard arguments in a case challenging the legality of a California law that mandates background checks each time a person buys ammunition for a firearm. A three-judge panel on the appeals court struck down the law as unconstitutional under the Second Amendment in 2025, with the panel finding the law “meaningfully constrains the right to keep operable arms.” The full court heard arguments in the case in a Pasadena courtroom.