Cook County Tells the Supreme Court AR-15s Are ‘Not in Common Use’ While Gun Groups Count 20 to 40 Million of Them

Estimated reading time: 5 minutes

CHICAGO, IL — Cook County has filed its brief with the Supreme Court of the United States in Viramontes v. Cook County, the challenge to the county’s ban on AR-15s and other semi-automatic rifles that the Court agreed to hear this summer. The filing goes out under the signature of Cook County State’s Attorney Eileen O’Neill Burke as counsel of record, and its own section headings tell you where the county is going: “The Relative Popularity of a Weapon Does Not Insulate It from Regulation” and “AR-15s Are Not in Common Use for Any Purpose That Immunizes Them from Regulation.”

The Second Amendment Foundation announced the filing on October 22, 2026, alongside Connecticut’s brief in the companion case, Grant v. Higgins. The brief’s caption lists both cases, Nos. 25-238 and 25-566, on writs of certiorari to the Seventh and Second Circuits, which simply means the justices agreed to review the lower appeals court decisions. Cook County is the respondent here, the party defending the ban. SAF says Viramontes was originally filed in 2021, that the county ordinance was the precursor to the nearly identical statewide ban Illinois passed later, and that SAF is joined in the case by the Firearms Policy Coalition and two private citizens. In Grant, SAF is joined by the Connecticut Citizens Defense League and three private citizens. Oral arguments in both cases are set for Wednesday, December 2.

The brief’s table of contents lays out a two-part case. Part one argues the ordinance fits within the nation’s tradition of regulating “unusually dangerous weapons,” that it is relevantly similar in purpose and operation to historical restrictions, and that it responds to dangers created by technological change and what the county calls unprecedented societal concerns. Part two goes after the common use test directly, arguing first that “Common Use Is Not Determinative of Constitutional Protection” and then that AR-15s are not in common use for any purpose that would shield them. The table of authorities shows the county reaching back to Aymette v. State, an 1840 Tennessee decision, and Cockrum v. State from Texas in 1859, alongside the recent en banc decisions in Bianchi v. Brown out of the Fourth Circuit and Association of New Jersey Rifle and Pistol Clubs v. Attorney General of New Jersey out of the Third, plus the Seventh Circuit’s Bevis v. City of Naperville and Barnett v. Raoul. En banc means the full appeals court heard the case rather than the usual three-judge panel. I have only the brief’s headings and table of authorities, not the full text of its argument, so my characterization of what Cook County argues rests on those headings and on SAF’s description of the filing.

That common use heading is the one I will be watching. Gun Owners of America estimates 20 to 40 million AR-15s are owned by Americans, and SAF founder Alan Gottlieb put the number at more than 30 million law-abiding owners in his statement on the briefs. Set those figures next to a heading that says AR-15s are not in common use for any purpose that matters, and the shape of the fight is clear. The county is not only disputing what the rifle is used for. It is arguing that the count should not decide the question at all.

SAF Executive Director Adam Kraut did not wait for the reply brief to answer. “Categorical bans on the most commonly owned rifles in America violate the Second Amendment, full stop,” he said, describing the bans as laws that “single out and demonize modern semi-automatic rifles for nonsensical reasons like the adjustability of a shoulder stock or angle of a grip.” Kraut said the opposition briefs attempt “creative” tactics to avoid the Court’s established standards or challenge them outright, and that SAF looks forward to filing its reply. Gottlieb was blunter: “It’s high time that assault weapons bans recede back into the primordial ooze of gun control legislation from which they emerged.”

The county’s brief lands in a case that has already drawn heavy amicus support on the other side. An amicus brief is a filing from someone who is not a party but wants the Court to hear its view. GOA and Gun Owners Foundation filed one on September 4 with Century Arms, Canik USA, B&T USA, and Fostech, arguing the government cannot ban commonly owned firearms because politicians or judges consider them too dangerous or military-style. “A favorable ruling would strike a major blow to some of the nation’s most extreme gun control laws, and states with ‘assault weapon’ bans will face a reckoning like never before,” GOA Senior Vice President Erich Pratt said. The NRA filed its own amicus brief the following day.

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• Koons Plaintiffs Tell Third Circuit: The Supreme Court Just Gutted New Jersey’s Carry Restrictions
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The stakes run well past the county line. SAF describes the Cook County ordinance as the model for the statewide ban, so every Illinois gun owner living under that law has a direct interest in how the justices treat the county’s arguments, and so does anyone in a state with a ban of its own. The mindset I bring to carry law applies here too: read what the government actually files, in its own words, before deciding what you think of it. That is why I quoted the county’s headings rather than paraphrasing them.

I will continue tracking Viramontes v. Cook County and Grant v. Higgins as the December 2 argument approaches.

Read the original story: Cook County Tells the Supreme Court AR-15s Are ‘Not in Common Use’ While Gun Groups Count 20 to 40 Million of Them