One of my clients recently came to me with a story about an assault weapons charge in Denver, Colorado. It is the kind of story every Colorado gun owner should hear, because it shows how fast a normal day at the range can turn into a criminal case.

This article is not legal advice. I am not an attorney. This is a training and awareness discussion from a firearms instructor who wants responsible gun owners to stay out of trouble.

The Traffic Stop

My client was driving home from a range in Northern Colorado when he was stopped in the Denver area for a traffic violation. He had been shooting a Glock 19 and an AK-style rifle. He also had magazines with him, including 17-round magazines for the Glock and 30-round magazines for the rifle.

The Glock 19 had a loaded 17-round magazine in it. The rifle was in the back seat in a case with no magazine inserted.

Trying to be responsible, he told the officers he had firearms in the vehicle. The officers asked him to step out of the vehicle. They examined the firearms and magazines, called supervisors, and at first made it sound like he would be on his way.

Instead, he was arrested.

Why the Glock Became the Problem

The charge centered on the Glock 19 with the 17-round magazine. The rifle, according to the information relayed to me, was not the basis of the charge because it did not have the 30-round magazine inserted at the time.

That is the part many gun owners do not understand. A handgun that seems ordinary in Pueblo, Fremont County, or other parts of Colorado may create a serious legal problem in Denver if it is paired with a magazine that holds more than 15 rounds.

Colorado’s 15-Round Magazine Limit

Colorado law generally treats a magazine that can accept more than 15 rounds as a large-capacity magazine. Under CRS 18-12-302, the sale, transfer, or possession of a large-capacity magazine can create criminal exposure unless an exception applies.

Do not make the common mistake of thinking, “I only loaded 15 rounds into it, so I’m fine.” The issue is generally what the magazine is capable of holding, not just how many rounds you placed in it that day.

If your magazine body is designed to hold 17 rounds, downloading it to 15 rounds does not magically turn it into a 15-round magazine.

Denver’s Assault Weapon Ordinance

Denver has its own local ordinance dealing with so-called assault weapons. Denver Municipal Code Sec. 38-130 includes definitions and restrictions that may be stricter than what gun owners expect under general Colorado law.

That is why I tell students this plainly: Denver is not Pueblo. If you travel into Denver with firearms or magazines, you need to know Denver’s rules before you go.

Get the Right Magazines

If you carry a handgun with factory magazines that hold more than 15 rounds, get smaller magazines for daily carry and travel inside Colorado. Many common handguns ship with 16-, 17-, or higher-capacity magazines. That does not mean those magazines are trouble-free under Colorado law or Denver ordinance.

For example, if you carry a Glock 19, consider using magazines that are actually manufactured to hold 15 rounds or fewer. Do not rely on downloading a larger magazine and hoping that solves the problem.

Keep Firearms Out of Sight During Travel

Colorado law allows lawful firearm ownership and transportation, but that does not mean every traffic stop will be simple. Keep your firearms properly secured, transported safely, and out of plain view when possible.

Also understand this: Colorado does not have a general legal requirement that every permit holder must immediately declare a firearm during an ordinary traffic stop. There may be situations where disclosure makes sense, and there may be situations where saying too much creates more problems. Use judgment, stay calm, and follow lawful commands.

The Law Is Being Challenged, But Do Not Bet Your Freedom on That

As of 2026, both Colorado’s magazine limit and Denver’s assault weapon ordinance have been the subject of federal legal challenges. That does not mean gun owners should ignore the law while cases work their way through court.

Until a court changes the practical reality, the safest course is simple: know the current rules, use compliant magazines, and do not assume that “everybody has these mags” is a defense.

Get Trained Before You Learn the Hard Way

Firearms training is not only about shooting better. It is also about understanding safe handling, transportation, storage, concealed carry responsibilities, and the legal issues that can wreck your life if you ignore them.

If you carry a handgun in Colorado, especially if you travel through Denver, Colorado Springs, Pueblo, or other cities, make sure your training is up to date.

Sources and Further Reading

• Denver Municipal Code Sec. 38-121 — Assault Weapons
• Colorado Revised Statutes 18-12-302 — Large-Capacity Magazines
• Handgunlaw.us — Colorado Firearms Law Summary