A line drawn through your property and your self-defense — and now the United States government says it’s unconstitutional.
Colorado’s magazine cap isn’t new: C.R.S. § 18-12-301/302, a 2013 law, makes it a crime to sell, transfer, or possess a magazine holding more than 15 rounds. For a decade it survived — until the Supreme Court’s Bruen decision changed the test, and a new challenger stepped in with far more weight than any before it.
On May 6, 2026, the United States Department of Justice sued Colorado to strike the 15-round limit down.
The biggest-caliber plaintiff of all three Colorado cases is the federal government itself. In United States v. State of Colorado & Colorado Dept. of Public Safety (No. 1:26-cv-01950, D. Colo., filed May 6, 2026), DOJ argues the 15-round cap violates the Second Amendment because magazines over 15 rounds are standard equipment for the most popular firearms in the country. Assistant Attorney General Harmeet Dhillon’s Civil Rights Division is leading it; the suit asks the court to bar enforcement outright, and it landed one day after a companion DOJ suit against Denver’s local assault-weapons ordinance. Attorney General Weiser is defending the law and calls the suit federal overreach.
The federal government isn’t alone. On June 30, 2026 — the same day the Supreme Court agreed to hear Viramontes v. Cook County, a challenge to an “assault weapons” ban — the Firearms Policy Coalition and the Colorado State Shooting Association, with three Denver residents (Ray Elliott, Trevor Alley, and Michael Vitco), filed Elliott v. Denver in federal court. Represented by Cooper & Kirk, they challenge Denver’s 1989 “assault weapons” ordinance and Colorado’s 15-round magazine cap, naming Denver, Governor Polis, Attorney General Weiser, CBI, and the State Patrol. The complaint’s core line: arms in common use — as these magazines “unquestionably are” — “cannot be unusual or dangerous.” Two suits, one target, and a Supreme Court term that may set the rule for both.
Rocky Mountain Gun Owners challenged the magazine ban under the Colorado constitution and lost — unanimously — at the Colorado Supreme Court in 2020. They refiled after Bruen in 2022 with the new federal framework in hand. The state-constitution route is dead; the Bruen route is the live one, and DOJ’s entry supersedes everything in weight — when the federal government sues a state over a gun law, that case is built to travel upward.
The national ground on magazine limits currently runs against the challengers: the Ninth Circuit upheld California’s ban en banc, and in 2025 the Supreme Court declined to take up the Rhode Island magazine case and Maryland’s AR ban — over noisy dissents from Justice Thomas and others. No one has yet won a final federal ruling striking a magazine cap. So the honest framing isn’t “the ban is doomed” — it’s that the United States government now agrees with Colorado gun owners that it’s unconstitutional, and the case is designed to make the Supreme Court finally answer.
If you want proof that magazine limits are infringement and the government knows it, look at Boulder. In 2022, Boulder, Boulder County, Superior, and Louisville each passed 10-round magazine limits — stricter than the state’s 15. Within weeks, federal judges restrained two of them, and rather than defend the rest, all four governments signed a stipulation agreeing to stop enforcing their bans. On November 3, 2022, Judge Nina Y. Wang made it a court order. That was nearly four years ago. The bans are still on the books, and they are still not being enforced — because the moment a federal court looked at a magazine limit through the Second Amendment’s actual lens, the governments’ lawyers folded rather than fight.
Now ask the obvious question: what constitutional principle makes 10 rounds an infringement but 15 rounds fine? There isn’t one. The standard magazine for the most common handguns in America holds 17; the standard magazine for the most common rifle holds 30. These aren’t “high capacity” — they’re the capacity the equipment comes with, owned by the tens of millions, which is precisely the common use test the Supreme Court applies. A limit of 15 is the same act as a limit of 10 — the state drawing an arbitrary line through your property and your self-defense — differing only in where the confiscation starts.
Boulder’s four-year retreat says the quiet part:
they suspect these limits can’t survive an honest courtroom.
The Department of Justice apparently agrees — it sued Colorado over the 15-round limit in May. The line isn’t 10 or 15. Under the Second Amendment, the state doesn’t get to draw one at all.
The precise history matters: the operative document is Doc. 38 in RMGO v. Town of Superior, No. 1:22-cv-02680 (D. Colo.) — an order approving a stipulation the parties signed, not a ruling that the ordinances are unconstitutional. Earlier temporary restraining orders hit Superior (July 2022) and Boulder County (August 2022) before the four cases were consolidated. Status today: stayed by agreement, not finally struck down; on August 28, 2026 the court stayed the whole case pending the Supreme Court’s decision in Viramontes v. Cook County. Colorado’s counter is that its own Supreme Court upheld the 15-round law in 2020 and no federal court has yet finally struck a magazine cap — true, but that 2020 ruling was under the state constitution, pre-Bruen, which is why the live action is all federal now.
The tax, the card-and-course gauntlet, and the magazine ceiling are on trial at once. The Colorado State Shooting Association is a plaintiff in the fight. Add your name and your support.
The author of this site is not an attorney and does not practice law. Nothing published here is legal advice, no part of it is offered as legal advice, and reading it creates no attorney-client relationship with anyone. This is Second Amendment advocacy and general-interest commentary written by a private citizen, and it includes opinion.
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