Supreme Court Receives First Volley of Briefs in Major AR-15 Ban Challenge

The Seventh and Second Circuit Courts of Appeals upheld bans on AR-15s by declaring the rifles "unusually dangerous" and functionally indistinguishable from military machine guns. But as the U.S. Supreme Court prepares to hear oral arguments on December 2, 2026, in the consolidated case of Viramontes v. Cook County, a massive wave of legal briefs—including a decisive and highly anticipated filing from the U.S. Justice Department—is setting the statistical and mechanical reality of the weapon directly against the lower courts' claims.[3][5]

The consolidated cases, which merge challenges to municipal bans in Cook County, Illinois, and statewide restrictions in Connecticut, represent the most consequential Second Amendment test since the 2022 Bruen decision. At stake is whether states and municipalities can categorically outlaw the possession and sale of specific semiautomatic rifles by labeling them "assault weapons." Gun rights advocates argue that this term is an arbitrary political invention rather than a technical classification, and that the bans criminalize the ownership of the most popular rifle platform in the United States.[2][3][5]

The lower courts relied heavily on the premise that AR-15s represent a dramatic technological change suited primarily for military combat rather than civilian self-defense. In upholding the bans, the Seventh Circuit characterized the AR-15 as a "militaristic weapon" capable of firing "300 rounds a minute," asserting that virtually no difference exists between the civilian semiautomatic rifle and the fully automatic M16 used by the armed forces. The Second Circuit similarly described the banned rifles as capable of "spray firing" and inflicting uniquely severe wounds.[2]

The opening volley of merits briefs, submitted ahead of the Court's September 2026 deadline, attacks those mechanical assertions directly. A coalition of firearms and ballistics experts—including a former FBI ballistics supervisor—filed an amicus brief noting that AR-15s are not machine guns and fire at the exact same rate as common handguns. The experts argue the rifles fire the same bullets at the same velocity as any other non-banned rifle of the same caliber, producing wounds that are generally less severe than those from other common hunting long guns.[2]

The core legal argument hinges on the "common use" standard established in the 2008 District of Columbia v. Heller decision, which protects arms typically possessed by law-abiding citizens for lawful purposes. To prove commonality, the challengers point to Professor William English's 2026 National Firearms Survey. The data shows that approximately 26.4 million American adults currently own at least one AR-15 or similarly styled semiautomatic rifle, with roughly 60 million such rifles in circulation nationwide, making it the paradigmatic American firearm.[2][4]

The U.S. Justice Department has thrown its full weight behind the challengers, a move that significantly alters the political calculus of the case. In a 40-page amicus brief filed by Solicitor General D. John Sauer and Assistant Attorney General Harmeet Dhillon, the federal government argued that categorical bans on such commonly owned rifles violate the Constitution. "A ban on a class of firearms burdens the right to keep and bear arms protected by the Second Amendment's plain text," the Justice Department wrote.[3]

The federal brief dismantles the lower courts' rationale by pointing to the sheer scale of civilian ownership and the lawful applications of the platform. "The AR-15 rifle is unquestionably in common use among law-abiding citizens for lawful purposes," the Justice Department stated, noting that the rifles are currently lawful at the federal level and in 40 states. The government emphasized that the overwhelming majority of owners possess the rifles for self-defense in the home, hunting, and target shooting—activities explicitly protected by the Second Amendment.[3][4]

Gun rights organizations have flooded the Supreme Court docket, filing 45 amicus briefs in support of the petitioners by the first week of September. Groups including the National Association for Gun Rights and the Firearms Policy Coalition highlighted the incongruity of the various bans across different jurisdictions. The Independent Institute's brief pointed out that Cook County bans a semiautomatic rifle if it has no stock, while Connecticut bans the exact same rifle if it does have a stock, illustrating the arbitrary and contradictory nature of the restrictions.[1][2][4]

Defenders of the bans argue that the regulations are critical public safety measures necessary to curb mass casualties in an era of frequent public shootings. The United States Conference of Catholic Bishops logged arguments in favor of keeping the bans, contending that "the adoption of firearm regulations by local authorities—be they municipal or state authorities—is consistent with both traditional principles of federalism and the Church's principle of subsidiarity." Other gun control groups maintain that the lethality of the weapons justifies their restriction.[3]

With oral arguments set for December 2, the Supreme Court's decision, expected by June 2027, will likely dictate the fate of similar bans in roughly a dozen other states. If the justices rule that the "common use" test strictly protects AR-15s based on their widespread ownership, it would severely limit the ability of states to restrict access to modern semiautomatic firearms. Such a ruling would fundamentally alter the landscape of American gun control, forcing state legislatures to abandon categorical bans in favor of alternative regulatory frameworks.[3][5]