What is the magazine limit in Colorado?
Last verified against primary sources: · Updated
Colorado's magazine limit is 15 rounds. A magazine that accepts, or can be readily converted to accept, more than 15 rounds is a "large-capacity magazine," and it is unlawful to sell, transfer, or possess one (C.R.S. §§ 18-12-301, 18-12-302). The offense is a class 1 misdemeanor after SB25-003 raised it from a class 2 on April 10, 2025.
There is an exception: you may keep a large-capacity magazine you owned before July 1, 2013 and have held continuously since. Magazines of 15 rounds or fewer are unrestricted under state law.
The 15-round threshold
The limit comes from the definition of "large-capacity magazine" in C.R.S. § 18-12-301 — the line is more than fifteen rounds, so a 15-round magazine is fine and a 16-round magazine is not:
'Large-capacity magazine' means: (I) A fixed or detachable magazine, box, drum, feed strip, or similar device capable of accepting, or that is designed to be readily converted to accept, more than fifteen rounds of ammunition
The statute sets separate, higher figures for shotgun magazines and excludes permanently altered magazines, .22 rimfire tubular devices, and lever-action tubular magazines.
What the ban covers, and the penalty
Section 18-12-302 makes it unlawful to sell, transfer, or possess a large-capacity magazine — possession is included, not just sales:
Except as otherwise provided in this section, a person who sells, transfers, or possesses a large-capacity magazine commits a class 1 misdemeanor.
Many older pages still call this a class 2 misdemeanor. That changed: SB25-003 raised it to a class 1 misdemeanor effective April 10, 2025 — the day the bill was signed, not the August 1, 2026 date that applies to the separate firearm rules. Possession during a felony or crime of violence is a class 6 felony.
The grandfather rule
You can lawfully keep a large-capacity magazine you owned on July 1, 2013 and have kept in continuous possession ever since (C.R.S. § 18-12-302(2)(a)). Both parts matter — pre-2013 ownership and unbroken possession. If you raise that defense, the statute puts the burden on the prosecution to disprove it (§ 18-12-302(2)(b)). Note also that there is no exception for magazines brought into Colorado from another state: because the ban reaches possession, keeping an out-of-state high-capacity magazine here is unlawful unless you qualify for the grandfather rule or an enumerated exception.
One local exception: Boulder
The City of Boulder has an ordinance limiting magazines to 10 rounds rather than 15 — but according to the city's own page, "The ban on assault weapons and large-capacity magazines has been paused" pending litigation (Rocky Mountain Gun Owners v. Town of Superior). We could not verify Boulder's exact codified text against a primary source, so this 10-round figure and its paused status come from the City of Boulder's program page. Denver, by contrast, matches the state's 15-round limit. Confirm any local rule with the jurisdiction before relying on it.
For the full breakdown — the definitions, exceptions, Denver and Boulder ordinances, and how this differs from the August 1, 2026 firearm law — see our Colorado magazine capacity hub.
Common questions
Are 30-round magazines legal in Colorado?
No, not to buy, sell, transfer, or possess — a 30-round magazine exceeds the 15-round limit in C.R.S. § 18-12-301 and is a "large-capacity magazine." The only way to lawfully possess one is under the grandfather clause: you owned it before July 1, 2013 and have kept it in continuous possession since.
Is a 15-round magazine legal in Colorado?
Yes. The limit is "more than fifteen rounds," so a magazine holding exactly 15 rounds or fewer is not a large-capacity magazine and is unrestricted under state law (C.R.S. § 18-12-301(2)(a)(I)).
What happens if you get caught with a high-capacity magazine in Colorado?
Selling, transferring, or possessing a large-capacity magazine is a class 1 misdemeanor (C.R.S. § 18-12-302), raised from a class 2 by SB25-003 in April 2025. If you possessed it during a felony or crime of violence, it is a class 6 felony. This page is reference information, not legal advice — if you are facing a charge, consult a Colorado attorney.