SB 25-003 was passed by the Democratic majority in the last regular legislative session and signed into law by Democratic Gov. Jared Polis, a defendant in the lawsuit, in April. But it doesn’t go into effect until August 2026.

The law will ban the purchases of semiautomatic rifles and shotguns that have detachable magazines, unless individuals get a “firearms safety course eligibility card” from their local sheriff department and then complete a firearm education course.

The bill, when it was initially introduced, was an outright ban on so-called “assault weapons,” but was later amended to include the permit-to-purchase requirements.

“The Act’s permit-to-purchase requirements for specified semiautomatic firearms arbitrarily delay and burden the right of law-abiding citizens to obtain and possess arms even if they have previously been determined to be law-abiding, and even if they desire to obtain and possess arms for the purpose of self-defense in the home, where Second Amendment protections are at their zenith,” said the lawsuit, filed Tuesday in the U.S. District Court for the District of Colorado.

The Colorado State Shooting Association, which is the National Rifle Association’s state affiliate, said in its announcement of the lawsuit that the law will place “unlawful burdens on the rights of law-abiding Coloradans.”

“This law won’t stop crime — it will only stop Coloradans from exercising their constitutional rights,” CSSA President Ray Elliott said. “Colorado already has background checks. We already have waiting periods. SB25-003 piles on yet another hoop for responsible citizens while criminals ignore the rules.

“Enough is enough,” Elliott said.

Mountain States Legal Foundation said the new law is “a direct affront to the Constitutional rights recognized” in the U.S. Supreme Court decisions District of Columbia v. Heller and New York State Rifle & Pistol Association v. Bruen.

“If the State of Colorado were to try these backhanded tactics to limit any other fundamental right – whether that be religion, speech, or the right to counsel – those statutes would be quickly struck down as unconstitutional by even the most partisan of jurists,” Michael McCoy, the MSLF director of the Center to Keep and Bear Arms, said in a statement. “But when it comes to the Second Amendment, these tactics to limit our God-given right to keep and bear arms for self-defense have borne fruit for far too many states … and for far too long. No more!”

McCoy added he’s confident the law won’t stand up in court.

“With the recent and clear precedent out of the United States Supreme Court and the Tenth Circuit upholding the Second Amendment protected rights of law-abiding citizens, SB3 will not be able to survive review and will be struck down,” he said. “I am confident of that.” 

MINNEAPOLIS SHOOTING REVIVES OLD GUN DEBATE IN NEW CONTEXT OF TRUMP CRIME PUSH

One of the lawsuit’s plaintiffs, Israel Del Toro, an Air Force veteran who survived an IED blast in Afghanistan that left him with burns on over 80% of his body, said the law would ban certain firearms and accessories that help him shoot despite physical limitations from his injuries, according to MSLF. One of those accessories, force-reset triggers, will be banned under the new law.

“Similarly, due to the difficulty that [Del Toro] experiences trying to hold a more traditional-style handgun with only one partially intact hand, Mr. Del Toro has come to rely on the more versatile AR platform semiautomatic pistol with stabilizing brace,” the lawsuit stated. “However, under the provisions of the Act, AR-platform pistols will become illegal to manufacture, sell or purchase …”