We wrote recently about how Colorado's 15-round magazine cap actually works — the statute, the definition, the July 2013 grandfather date. What we didn't get into is that the law itself, along with Denver's separate "assault weapons" ordinance, is currently being challenged in federal court by two entirely different plaintiffs, running two entirely different legal theories, at the same time.
The federal government's lawsuit
On May 6, 2026, the Justice Department's Civil Rights Division sued the State of Colorado directly, arguing that the magazine cap — C.R.S. 18-12-302, the same statute we broke down in our last post — unconstitutionally bans magazines that "come standard with many of the most popular firearms in the Nation, including AR-15-style rifles." The department's announcement leaned on District of Columbia v. Heller's holding that the Second Amendment protects weapons "in common use for lawful purposes," arguing that a magazine owned by hundreds of millions of law-abiding Americans can't be banned outright. Assistant Attorney General Harmeet Dhillon, who heads the Civil Rights Division, called the law "political virtue signaling at the expense of Americans' constitutional right to keep and bear arms." The DOJ filed a second, separate suit against the City of Denver over its own local assault-weapons ordinance around the same time.
What's genuinely unusual here, according to reporting on the case, is the legal vehicle: DOJ's Civil Rights Division is reportedly proceeding under authority Congress usually reserves for "pattern or practice" civil rights investigations — the kind of tool historically used against police departments accused of systemic misconduct — rather than a more conventional Second Amendment challenge brought by an injured private party. Whether that vehicle holds up procedurally is itself a live question in the case, separate from the underlying constitutional argument.
The private lawsuit — a different legal theory entirely
Then, on June 30, 2026, a second and completely separate suit landed in the same federal district: Elliott v. Denver, filed by the Colorado State Shooting Association and the Firearms Policy Coalition on behalf of three individual Denver-area gun owners — Ray Elliott, Trevor Alley, and Michael Vitco. This one runs the traditional playbook: private citizens claiming their own Second Amendment rights are burdened by Denver's assault-weapons ban and Colorado's statewide magazine cap, asking the court to apply the Bruen text-and-history test directly to both laws.
The practical result is that Colorado and Denver are now defending the same two laws — the state magazine cap and Denver's local assault-weapons ordinance — against both the executive branch of the federal government and a private gun-rights coalition, in parallel, in front of the same court.
The backdrop that could decide both cases without either court needing to
Neither Colorado case exists in a vacuum. On June 30, 2026—the same day Elliott was filed—the U.S. Supreme Court granted review in two consolidated cases, Viramontes v. Cook County and Grant v. Higgins, concerning whether the Second and Fourteenth Amendments protect possession of semiautomatic rifles in common use for lawful purposes, including AR-15-style rifles. Briefing is underway, with a decision expected during the Court's 2026–27 term.
That review may directly affect the challenge to Denver's rifle restrictions and may influence how lower courts analyze commonly owned arms. But the question accepted by the Supreme Court concerns semiautomatic rifles, not Colorado's 15-round magazine limit standing alone. It is therefore too early to say Viramontes and Grant will necessarily resolve the magazine claims in either Colorado lawsuit.
What this means if you're in Colorado right now
Nothing has changed about current law. C.R.S. 18-12-302 and Denver's local ordinance remain fully in effect, exactly as we described in our last post — the grandfather date is still July 1, 2013, continuous possession is still required, and none of this litigation has produced an injunction pausing enforcement of either law. What's changed is the durability of the legal ground both laws are standing on: they're now being tested from two directions in Colorado specifically, on top of a nationwide Supreme Court case that could settle the question for every state with a similar law, Colorado included, sometime in 2027.
As always, we are not lawyers—just Colorado citizens trying to understand the rules, statutes, and court decisions and share what we learn. The information on this website is for general informational purposes only and does not constitute legal advice, nor does it create an attorney/client relationship. The accuracy, completeness, or currency of the content is not warranted. Your use of content on this website is at your own risk. Consult an attorney about your specific circumstances.
