Colorado - CO Gun Laws

Currently, no state permit is required to purchase most firearms, just the standard federal background check through a licensed dealer. That changes August 1, 2026, when SB25-003 takes effect, requiring a permit and two background checks before buying certain semi-automatic firearms specifically, not a blanket requirement across all firearm types. A 3-day waiting period applies after the background check clears before the buyer can take possession.

Colorado requires a background check for all firearm sales, including private transactions between individuals, even at gun shows, private-party sales have to go through a licensed dealer or the state-run system. No family exemption applies.

Standard federal disqualifying categories apply. Colorado has its own red flag / Extreme Risk Protection Order law allowing family, household members, or law enforcement to petition a court to temporarily remove firearms from someone found to pose a significant risk.

Legal without a permit in most of the state for adults 18 and older, though Denver and a handful of other localities have their own additional restrictions, worth checking local rules before assuming statewide open carry applies exactly the same way everywhere.

Colorado is shall-issue, permits are issued to county residents through their local sheriff's office. As of July 1, 2025, training requirements increased to 8 hours including a live-fire component.

Consistent with the state's permit framework for concealed carry, no separate vehicle-specific permit applies beyond the underlying carry authorization.

Standard categories: schools, courthouses, and posted government buildings, plus whatever additional restrictions apply locally, Denver especially maintains its own layered rules given the state's weak preemption.

Colorado generally follows the federal floor for possession, with dealer sales requiring 18 for long guns and 21 for handguns consistent with federal law.

Colorado caps magazine capacity at 15 rounds; magazines manufactured after July 1, 2013 that exceed that limit are prohibited. There is no statewide ban on any category of semi-automatic firearm, though Denver and a few other localities maintain their own local assault weapon restrictions on top of the state baseline. Starting August 1, 2026, SB25-003 adds a permit-to-purchase requirement with two background checks specifically for certain semi-automatic firearms, this is a new acquisition hurdle, not a possession ban, and is worth re-checking closely once it actually takes effect.

Colorado has no stand-your-ground statute, but the state supreme court has consistently held there's no duty to retreat in public for someone lawfully present who isn't the aggressor. Colorado's Castle Doctrine, known as the "Make My Day" law (C.R.S. § 18-1-704.5), is genuinely strong within its scope, no duty to retreat at all when an intruder is inside your residence, but it's narrowly limited to the residence itself, shared hallways, lobbies, and other common areas of an apartment building generally don't count, and the doctrine doesn't extend to a vehicle or place of business the way some other states' Castle Doctrine laws do.

Weak. Colorado became the first state in the nation to broadly repeal the majority of its own firearms preemption statute in 2021. Local governments can now enact their own ordinances governing the sale, purchase, transfer, or possession of firearms, ammunition, or accessories, provided they're not less restrictive than state law, only more. Denver is the clearest example of a locality taking advantage of that room.

- Colorado Bureau of Investigation, Concealed Handgun Permits: cbi.colorado.gov
- Colorado Revised Statutes, Title 18, Article 12 (weapons): leg.colorado.gov
- Your local county Sheriff's office, the licensing authority for concealed carry permits
- ATF: for federal NFA questions, suppressors are legal in Colorado for owners who comply with the National Firearms Act, Denver maintains some of its own additional local rules