Buying certain firearms will be notably more onerous starting Saturday as one of Colorado’s most consequential gun regulations goes into full effect.
requires Coloradans looking to buy rifles and shotguns with detachable magazines or gas-operated pistols — weapons popularly conceived of as assault-style rifles — to first obtain an eligibility card from a sheriff’s office and pass a course by a verified instructor. This new requirement stacks with prior background check and waiting period requirements.
The measure passed in 2025 and was signed into law by Gov. Jared Polis, but included delayed implementation to allow time to set up rules and procedures.
In the lead-up, developed a curriculum that trainers must follow, the Department of Revenue compiled a list of some affected by the regulation, and the Colorado Bureau of Investigation cross-trained 20 of its staffers to double its capacity for conducting background checks. Hundreds of instructors across Colorado registered with the state to offer training.
Meanwhile, a lawsuit seeking to block the law on Second Amendment grounds has continued through the judicial process. Backers said they’re considering asking for a preliminary injunction to stop the law’s enforcement while the court deliberations continue.
The County Sheriffs of Colorado, an advocacy organization, said its members are committed to carrying out their role in the new rules, but also called the law an unfunded mandate that will be borne by local governments.
Backers of the new law are nonetheless celebrating the rollout as a milestone in state officials’ quest to regulate firearm access to prevent gun violence, and as a landmark for other states to follow.
“Colorado is proving that passing a strong gun safety law is only the beginning. Successful implementation is what transforms policy on paper into lives saved,” Justin Wagner, senior vice president of law and policy at Everytown for Gun Safety, said in a statement. “This law gives states across the country a roadmap for implementing innovative policies that keep communities safe while providing clarity for responsible gun purchasers, retailers and law enforcement.”
Polis defended the law as something that “protects Coloradans’ Second Amendment rights and ensures a well-trained and educated gun ownership community,” spokesman Eric Maruyama said in a statement.
“This law ensures those who purchase certain weapons receive proper education and safety training, which will certainly help make our communities safer and reduce gun violence,” Maruyama said. “Governor Polis is confident this law will make us safer while protecting Coloradans’ Second Amendment Rights.”
Sen. Tom Sullivan, a Centennial Democrat and one of the chief architects of Colorado’s modern firearm regulation, said the new law is a continuation of past efforts, such as the 15-round limit on magazines passed in 2013 after the Aurora theater massacre. Sullivan’s son died in that shooting.
“High-capacity magazines are what put the ‘mass’ into mass shootings, which is why over a decade ago Colorado Democrats passed legislation to prohibit magazines that hold over 15 rounds of ammunition,” Sullivan said in a statement. “This law further enforces that ban. It will save lives and increase safety for all Coloradans. The people of Colorado have mandated that we do something about the public health crisis that is gun violence, so thatap exactly what we’re doing.”
Classes, eligibility cards and increased costs
The new law does not cover all guns, but a subset of semiautomatic rifles and shotguns with detachable magazines, or gas-operated semiautomatic pistols. Bolt-action hunting rifles, revolvers and recoil-operated semiautomatic handguns, like common Glock models, are not covered.
Buyers of firearms covered by the law need to pass a background check and apply for an eligibility card through a sheriff’s office. Applicants can go through any sheriff’s office, though several charge higher fees for non-county residents.
Once the person’s eligibility is established, they will need to take and pass an in-person class on general gun safety to take possession of the gun.
The primary class takes 12 hours, across at least two days, and covers things like basic handling of firearms, child safety and safe storage of firearms, firearm deaths associated with mental illness, extreme risk protection awareness, and victim awareness and empathy, Colorado Parks and Wildlife spokesperson Travis Duncan said in an email. The agency declined to make a person available for an interview ahead of the new law’s implementation.
Once the class is passed, a firearm dealer can then sell a covered gun to a prospective buyer.
Ray Elliott, president of the Colorado State Shooting Association, a gun-rights group, argued SB3 de facto went into effect days ahead of the law’s stated effective date of Aug. 1. People need to pass the three-day waiting period and a background check to accept possession of a gun; if they waited until a day or two before the effective date, they’d still need to go through the training course — and the hundreds of dollars that can cost, plus the two days of classes — before they could acquire their new gun.
In some cases, itap not clear whether every county has an available trainer, and different sheriff’s offices have been rolling out procedures for their role in the new law at different paces, Elliott said.
A posted on Colorado Parks and Wildlife’s website, for example, only specifies trainers in 47 counties, though some advertise as being available statewide and instructors aren’t limited to just the counties they list.
“People wanting to buy firearms are extremely upset over what’s going to happen now,” Elliott said, noting that the new training and eligibility requirements could potentially double the cost of buying a covered firearm. “I think you’re going to have an uproar. And it’s already beginning.”
His group has also sued the state over the law, arguing it violates the Second Amendment. He said his lawyers are watching for access issues to the eligibility cards and classes in preparation for seeking an injunction to stop the law from being enforced, though that decision won’t be made until next week, he said.
“A right delayed is a right denied,” Elliott said. “Before you put this into effect, it’s up to you to have the processes and procedures in place.”
Sgt. Shea Haney, a spokesperson for the Adams County Sheriff’s Office, said his agency has been working to issue eligibility cards ahead of the Aug. 1 requirement for training. The sheriff there also hired two people to handle issuing the eligibility cards in anticipation of the demand. He said there’s been “some confusion” and “some frustration” with the new law.
“We understand the frustration folks feel any time these sort of laws come down like this,” Haney said. “People have a lot of opinions, and rightfully so, but we want to make sure people know this is not a mandate from the sheriff or Adams County. This is just something we have to comply with to help our citizens get what they need to get.”
Other sheriff’s offices are handling the rollout of SB3 differently. The Jefferson County Sheriff’s Office, for example, was waiting until the law went into full effect before it began processing applications for the eligibility card. Spokesperson Mark Techmeyer said there’s “continuing confusion” for both law enforcement and the public about background checks. His office will not recommend background check vendors, and leaves that responsibility on applicants to find one that satisfies state requirements, he said in an email.
“(Our records staff) have also heard considerable frustration from members of the public regarding the legislation,” Techmeyer said in a statement. “The Sheriff’s Office did not create the law, but we are prepared to fulfill our responsibilities under it and will conduct the required reviews with due diligence.”
‘We all agree training is essential’
On the training side, firearm instructor Alicia Garcia said she and her partner at Concealed Carry Classes of Denver have been trying to rejigger their schedule to account for the normal groups looking for ongoing training or for concealed carry permits and the people who now need these new classes.
And, despite potentially reaping financial benefits from the extra work, she has philosophical problems with the requirement. Garcia has previously sued the state over its three-day waiting period for firearms.
She worried the new class requirement will make people think of firearm training as a box to check, not a part of responsible gun ownership. She would rather the state fund free gun safety and de-escalation training.
The prescribed curriculum also limits instructors and locks them into some “archaic” thinking around gun safety, she said. As one example, she disagreed with the mandated characterization of “accidental discharges.” There are no accidents with guns, Garcia said, only negligence around the tool and its use — a subtle but important reframing to her.
“We all agree training is essential,” Garcia said. “We all want people to make firearms training, firearm safety, a defensive mindset, and things of that nature, a priority in life. We just don’t believe it should be forced on you.”
