Boulder gun laws
Last verified against primary sources: · Updated
In June 2022 the City of Boulder passed a package of six firearms ordinances (Nos. 8494 and 8525–8529) that, on paper, are among the strictest in Colorado: an assault-weapons ban, a 10-round magazine limit, a raised purchase age of 21, sensitive-place and open-carry bans, ghost-gun rules, dealer signage, and a 10-day waiting period.
The crucial caveat: Boulder voluntarily paused enforcement of its assault-weapons and large-capacity-magazine bans in August 2022, pending litigation, and that pause still appears to be in effect. The other measures — including the open-carry ban, the trigger-activator ban, ghost-gun rules, dealer signage, and the waiting period — remain in force.
Why Boulder can set its own rules
Boulder's gun ordinances rest on Colorado's 2021 preemption law, which lets local governments regulate firearms more strictly than the state. (Boulder's earlier, pre-2021 assault-weapons ban had been struck down by a state court as preempted; the city re-enacted its restrictions after the law changed.)
Unless otherwise expressly prohibited pursuant to state law, a local government may enact an ordinance, regulation, or other law governing or prohibiting the sale, purchase, transfer, or possession of a firearm, ammunition, or firearm component or accessory that a person may lawfully sell, purchase, transfer, or possess under state or federal law.
A note on how this page is cited. Boulder's official municipal-code host blocks automated access, so we could not independently verify the exact codified text of the Boulder Revised Code (reported at BRC §§ 5-8-10, 5-8-25, and 5-8-28). Everything below is cited to Boulder's own ordinance numbers and the City of Boulder's official pages — not to a verbatim quote of the code. We do not reproduce Boulder Revised Code language here because we could not confirm it word-for-word.
The six 2022 ordinances
The City Council passed all six unanimously on June 7, 2022. As documented by the city's own agenda portal and news release:
| Ordinance No. | Subject |
|---|---|
| 8494 | Bans assault weapons, large-capacity magazines, and rapid-fire trigger activators; raises the firearm-purchase age to 21; repeals the city's prior (2018) ordinances |
| 8525 | Prohibits carrying firearms in certain public ("sensitive") places |
| 8526 | Regulates unfinished frames and receivers and unserialized firearms (ghost guns) |
| 8527 | Prohibits open carrying of firearms in public places |
| 8528 | Requires firearm dealers to post warning signage (English/Spanish) at point of sale |
| 8529 | Imposes a waiting period before a firearm sale may be completed |
Key specifics reported by the City of Boulder:
- Assault-weapons ban applies prospectively — it bans possession of covered weapons purchased after July 1, 2022, grandfathering weapons lawfully owned before then.
- Magazine limit: more than 10 rounds is prohibited. This is stricter than both Colorado's statewide 15-round limit and Denver's 15-round line. See Colorado's 15-round magazine limit.
- Purchase/possession age raised from 18 to 21.
- Sensitive places named in the city's own materials include public buildings, polling places and ballot-counting centers, banks, theaters, courthouses, hospitals, and businesses that serve alcohol — described by the city as non-exhaustive.
The waiting period: 10 days, and still enforced
Ordinance No. 8529 imposes a 10-day waiting period after a background check is initiated before a firearm sale may be completed — described by legal commentators as likely the most restrictive such waiting period in Colorado, and far longer than Colorado's statewide waiting period. Unlike the assault-weapons and magazine bans, this measure is not part of the paused enforcement. See Colorado's statewide waiting period for the state rule this contrasts with.
What is paused — and what is not
Boulder's assault-weapons ban and 10-round magazine ban are on the books but not currently being enforced by the city's own choice. The City of Boulder voluntarily paused enforcement of those two provisions in August 2022 "to allow time for more legal coordination among neighboring jurisdictions," after Rocky Mountain Gun Owners won temporary restraining orders against neighboring Superior and Boulder County. As of our July 20, 2026 review, that pause still appears to be in effect — we found no city announcement resuming enforcement. Treat Boulder's assault-weapons and magazine bans as true-on-paper but not actively enforced.
The remaining measures — the open-carry ban (Ord. 8527), the rapid-fire trigger-activator ban (part of Ord. 8494), the ghost-gun rules (Ord. 8526), the dealer-signage requirement (Ord. 8528), and the 10-day waiting period (Ord. 8529) — remain in effect and enforced, per the city.
The underlying litigation, Rocky Mountain Gun Owners v. Town of Superior (D. Colo.), remained unresolved as of a July 17, 2025 federal court order that allowed the challenge to Boulder's and Boulder County's assault-weapons and large-capacity-magazine provisions to proceed and ordered further briefing. Because the case is still open and the pause has not been lifted, the pause is the operative posture.
Boulder County and neighboring towns are separate
The City of Boulder's ordinances are distinct from those of Boulder County (unincorporated areas), which passed its own similar package (County Ordinance No. 2022-5) in August 2022, also under a litigation-driven enforcement pause as to its assault-weapons and magazine provisions. Nearby Louisville and Superior adopted parallel 2022 packages as well and were likewise sued. If you are outside Boulder city limits, check which government's rules apply where you are.
Common questions
Are assault weapons illegal in Boulder?
They are banned on paper but the ban is not currently being enforced. City of Boulder Ordinance No. 8494 (2022) prohibits assault weapons purchased after July 1, 2022, but the city voluntarily paused enforcement of that ban — and its magazine ban — in August 2022 pending litigation, and the pause still appears to be in effect as of July 20, 2026. Weapons lawfully owned before July 1, 2022 are grandfathered in any event.
What is the magazine limit in Boulder?
Boulder's ordinance bans magazines that hold more than 10 rounds — stricter than Colorado's statewide 15-round limit. However, enforcement of Boulder's large-capacity-magazine ban is currently paused by the city along with its assault-weapons ban, pending litigation. Colorado's statewide 15-round limit still applies in Boulder regardless.
Is there a waiting period to buy a gun in Boulder?
Yes — Boulder Ordinance No. 8529 imposes a 10-day waiting period after a background check is initiated before a sale may be completed, and this measure remains in effect (it is not part of the paused enforcement). That is longer than Colorado's statewide waiting period. See Colorado's statewide waiting period.
Can you open carry in Boulder?
No. City of Boulder Ordinance No. 8527 (2022) prohibits open carrying of firearms in public places, and this ordinance remains in effect. Colorado state law allows local governments to ban open carry in this way (C.R.S. § 29-11.7-104).
Is Boulder stricter than the rest of Colorado?
Yes — on paper Boulder's 2022 ordinances are among the strictest in Colorado, with a 10-round magazine limit (vs. the state's 15), a 10-day waiting period, an age-21 requirement, and open-carry, ghost-gun, and assault-weapons bans. In practice, the assault-weapons and magazine bans are paused pending litigation, while the open-carry ban, waiting period, dealer signage, ghost-gun rules, and trigger-activator ban remain enforced.
Primary sources for this page
- Gun Violence Prevention Ordinances — City of Boulder (official)
- City Council unanimously passes six gun violence prevention measures — City of Boulder (June 2022)
- City voluntarily pauses enforcement of assault-weapons ban — City of Boulder
- Six-ordinance coversheet (Ords. 8494, 8525–8529) — City of Boulder agenda portal
- Federal judge partially allows challenge to Boulder/Boulder County gun ordinances — Colorado Politics (July 17, 2025)
- C.R.S. § 29-11.7-103 (local firearms regulation permitted) — OLLS 2024 codification