The Department of Justice has filed a major lawsuit challenging Colorado’s ban on standard-capacity magazines, marking one of the biggest federal Second Amendment actions in recent years. The lawsuit argues that magazines holding more than 15 rounds are commonly owned by law-abiding Americans and are protected under the Second Amendment. Filed in federal court, the DOJ claims Colorado’s law violates constitutional rights by banning firearm magazines that are widely used for lawful purposes across the country.

According to the complaint, the DOJ is relying heavily on the Supreme Court’s decision in District of Columbia v. Heller and the Bruen standard, arguing that firearm magazines are protected “arms” under the Constitution. The lawsuit also rejects the term “large-capacity magazines,” instead referring to them as “standard-capacity magazines” because they come standard with many popular firearms, including AR-15 style rifles. The DOJ states that millions of Americans legally own these magazines for self-defense, sport shooting, and other lawful activities.

The case was filed by the DOJ’s Civil Rights Division, led by Assistant Attorney General Harmeet Dhillon, who has repeatedly stated that the Second Amendment should be treated like every other constitutional right. The lawsuit claims Colorado cannot provide any historical tradition supporting a ban on commonly owned magazines, which is now required under the Supreme Court’s Bruen framework. The DOJ is asking the court to block enforcement of the law and declare the magazine ban unconstitutional.

This lawsuit could have major implications nationwide, especially as other magazine ban cases remain pending before the Supreme Court. Legal experts believe the federal government’s involvement adds significant weight and could eventually create a pathway for the Supreme Court to finally address magazine bans directly. For gun owners and Second Amendment advocates, the DOJ’s action signals a major shift away from the aggressive firearm policies seen during the Biden administration and could reshape the future of magazine ban litigation across the United States.