Colorado’s magazine law bans the sale, transfer, and possession of any firearm magazine that holds more than 15 rounds of ammunition. The restriction has been in effect since July 1, 2013. If you owned a larger magazine before that date, you can keep it under a grandfather clause, but only if you have maintained continuous possession the entire time. Every violation is a class 2 misdemeanor.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
What the 15-Round Limit Covers
A large-capacity magazine, under Colorado law, is any fixed or detachable magazine, box, drum, feed strip, or similar device that can accept more than 15 rounds. The definition also reaches devices designed to be readily converted to hold more than 15. A 15-round magazine sold with an extension kit that pushes it past the limit counts as a large-capacity magazine from the start.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
Shotguns are measured differently. A fixed tubular shotgun magazine is banned if it holds more than 28 inches of shells, including any extension. A nontubular detachable shotgun magazine is banned if it accepts more than eight shells when combined with a fixed magazine.2CBI. Colorado Revised Statutes 18-12-301 – Definitions
Magazines the Ban Does Not Reach
Three categories sit outside the ban entirely, regardless of when you acquired them:
- Magazines that have been permanently altered so they cannot accept more than 15 rounds.
- Attached tubular devices designed to accept and operate only with .22 caliber rimfire ammunition. That covers most .22 rifles with tube-fed magazines.
- Tubular magazines contained in lever-action firearms, regardless of capacity.
If you own a lever-action rifle or a .22 with a tubular magazine, the 15-round limit does not apply to those guns even when the tube holds well over 15.2CBI. Colorado Revised Statutes 18-12-301 – Definitions
The Pre-2013 Grandfather Clause
Magazines owned on or before July 1, 2013, are legal to keep, but the statute requires continuous possession. You cannot lend the magazine, give it away, or let someone else hold it, even briefly. Once continuous possession is broken, you cannot legally get the magazine back.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
On paper, the burden runs in your favor. If you are charged and claim the grandfather exception, the prosecution has to prove your magazine was not owned before the cutoff. You do not have to prove it was. In practice, Colorado runs no registration system for magazines, so a defense without any supporting evidence is difficult to mount. Purchase receipts, dated photographs, and bank records showing pre-2013 purchases are the kind of documentation that actually holds up.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
The statute does not say whether disassembling a grandfathered magazine for cleaning or replacing a worn spring counts as breaking continuous possession. No Colorado court has resolved the question. Routine maintenance where the magazine never leaves your control is the safer reading; handing it to a gunsmith is the riskier one.
Buying, Selling, and Bringing Magazines Into the State
The ban is not limited to new purchases at a Colorado gun store. Selling, transferring, or possessing a large-capacity magazine is illegal unless the grandfather clause or another exemption applies. You cannot buy one from a dealer, receive one as a gift, inherit one, or bring a newly acquired one in from another state.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
Licensed dealers cannot sell large-capacity magazines to civilians. They can hold them only for sale to law enforcement or military buyers, or for manufacturing operations where the magazines will move out of state or to exempt purchasers.
Traveling Through Colorado
Traveling through the state with magazines that are legal at home carries real risk. The federal Firearm Owners Protection Act protects travelers moving lawfully owned firearms between states where they can legally possess them, provided the guns are unloaded and stored properly. Federal courts have held that this safe-passage protection does not shield you from state laws banning specific magazine types. A driver passing through Colorado with a 30-round magazine can be charged even when the magazine is legal at both the origin and destination. The safe approach is to leave large-capacity magazines at home or ship them separately around the state.
Marking Rule for Colorado-Made Magazines
Any large-capacity magazine manufactured or assembled in Colorado after July 1, 2013, must carry a permanent, legible stamp or engraving on its outer surface showing it was made after the ban took effect. That marking helps distinguish post-ban magazines from grandfathered ones. Out-of-state manufacturers are not bound by the marking rule, but their products remain illegal for civilian sale or possession in Colorado.3Colorado Public Law. Colorado Revised Statutes 18-12-303 – Identification Markings for Large-Capacity Magazines
Penalties and Collateral Consequences
Every violation is a class 2 misdemeanor, whether the charge is possession, sale, or transfer. The statute does not distinguish between someone who unknowingly drove into the state with a magazine and someone actively distributing them.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
A class 2 misdemeanor in Colorado carries up to 120 days in jail, a fine of up to $750, or both.4Colorado Revised Statutes. Colorado Code Title 18 Article 1.3 Part 5 Section 18-1.3-501 – Misdemeanors Classified – Penalties
Those numbers understate the impact. A conviction leaves a criminal record that can affect employment, housing, and professional licensing. Officers can confiscate prohibited magazines during any lawful encounter, and prosecutors can add a separate count for each magazine involved.
Effect on Federal Firearm Rights
A Colorado magazine conviction alone does not strip your federal right to own firearms. Federal law disqualifies people convicted of crimes punishable by more than one year of imprisonment, but it carves out state misdemeanors punishable by two years or less. Colorado’s class 2 misdemeanor tops out at 120 days, well inside that carve-out.5Office of the Law Revision Counsel. 18 U.S. Code 921 – Definitions
Who Is Exempt
Active-duty law enforcement officers can possess and use large-capacity magazines in the course of official duties, at any level of government. Members of the U.S. Armed Forces and the Colorado National Guard are exempt when acting within the scope of their military duties; off-duty or personal use is not covered.
Retired officers get less protection than many assume. The federal Law Enforcement Officers Safety Act (LEOSA) lets qualified retired officers carry concealed firearms nationwide, overriding most state and local restrictions.6Office of the Law Revision Counsel. 18 U.S. Code 926C – Carrying of Concealed Firearms by Qualified Retired Law Enforcement Officers LEOSA does not preempt state magazine limits. Federal guidance from U.S. Customs and Border Protection states this directly: retired officers carrying under LEOSA still have to comply with any state law restricting rounds per magazine.7CBP. CBP Law Enforcement Officers Safety Act (LEOSA) Information Sheet A retired officer carrying a 17-round magazine in Colorado faces the same charges as any other civilian.
Licensed firearms manufacturers and dealers can possess large-capacity magazines only for limited purposes: manufacturing them for exempt buyers, transferring them to out-of-state entities, or operations that keep the magazines out of Colorado civilian hands.1Colorado Revised Statutes. Colorado Code Title 18 Article 12 Part 3 Section 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
Where the Law Stands Now
Enforcement varies by county. Shortly after the ban took effect, roughly half of Colorado’s county sheriffs publicly opposed the law, and some rural jurisdictions have treated it as a low priority ever since. Where the ban is enforced, it usually surfaces during other police interactions, such as traffic stops or searches incident to arrest. Living in a county with a sheriff who has deprioritized the law does not make possession legal. A state trooper, a federal agent, or a newly elected sheriff can still enforce the statute.
The ban has survived its major state challenge. In Rocky Mountain Gun Owners v. Polis, the Colorado Supreme Court upheld the law in 2020, calling it a reasonable exercise of the police power that neither nullified nor effectively destroyed the right to bear arms under the Colorado Constitution.8Justia Law. Rocky Mountain Gun Owners v. Polis – 2020
The federal picture has changed since then. The U.S. Supreme Court’s 2022 decision in New York State Rifle & Pistol Association v. Bruen reset the framework for evaluating firearms regulations, requiring the government to show a challenged law is consistent with the nation’s historical tradition of firearms regulation. Colorado’s 15-round ban has not yet been tested under Bruen in federal court. Related litigation is moving: in September 2025, the Colorado State Shooting Association filed a federal challenge to Senate Bill 25-003, a 2025 law adding restrictions on semiautomatic firearms with detachable magazines, which is set to take effect on August 1, 2026.
Until a court rules otherwise, the 15-round limit is fully enforceable. Possessing a prohibited magazine today carries the same legal risk it did in 2013.