How did we get here?
Senate Bill 3 — formally SB25-003 — didn’t appear out of nowhere. It was the culmination of several trends that had been building in Colorado politics for years:
Colorado’s legislature shifted hard toward gun-control policy after 2019
Once Democrats gained a durable trifecta (House, Senate, Governor), firearm legislation became a recurring priority every session. That included:
Red flag laws
Expanded background checks
Waiting periods
Dealer regulations
Ghost gun restrictions
Magazine restrictions
Firearm industry liability laws
SB3 was basically the next escalation step: moving from regulating transactions and accessories into regulating categories of firearms themselves.
The original bill was much more aggressive
Early versions of SB3 were closer to a straightforward “assault weapon” ban:
Ban manufacture
Ban sale
Ban transfer
Ban purchase
…of semiautomatic firearms with detachable magazines.
That ran into:
resistance from moderates,
implementation concerns,
likely constitutional challenges,
pressure from Gov. Jared Polis.
So lawmakers softened it into a permit/training system instead of a total prohibition.
That compromise became:
training requirements,
sheriff vetting,
eligibility cards,
fixed-magazine carveouts.
Essentially:
“You can still buy these firearms, but only after state-approved training and screening.”
Why semiautomatics with detachable magazines?
Because that category captures:
AR-pattern rifles
AK-pattern rifles
many tactical shotguns
some pistols
The detachable magazine became the legal hook because courts have historically allowed more regulation around “features” and “dangerousness” arguments tied to mass shootings.
Why did it ultimately pass?
A few reasons:
Democrats had the votes.
Public opinion in urban Front Range areas trends more supportive of gun restrictions than rural Colorado.
National momentum after repeated mass shootings.
The compromise/training carveout pulled enough moderates onboard.
Opposition was large but fragmented:
sheriffs,
gun groups,
dealers,
rural counties,
instructors,
Republican legislators.
There was extensive public testimony against the bill, and it was amended dozens of times before passage.
The big-picture answer
“How did we get here?” is really:
Years of incremental gun legislation
Repeated high-profile shootings in Colorado
Democratic legislative control
A strategic pivot from outright bans toward regulated access systems
Political compromise to make the bill survivable legally and politically
SB3 became the bridge between:
traditional Colorado gun culture
anda California/Washington-style regulatory model.
Exceptions (from CPW website)
Specified Semiautomatic Firearms do not include:
Most semiautomatic hunting shotguns are exempted with these provisions.
Rimfire .22 caliber or lower firearms, unless the firearm has a separate upper and lower receiver.
A firearm that is manually operated by a bolt, pump, lever, or slide action.
A semiautomatic firearm with a permanently affixed magazine that is limited to 15 rounds of ammunition or fewer.
A single- or double-action semiautomatic handgun that uses recoil to cycle the action of the handgun.
A firearm that has been made permanently inoperable
An antique firearm or curio or relic; Certain models of firearms, as they exist and are configured on August 1, 2026 as described in CRS 18-12-116(1)(d)(II)(e)
What does SB3 do?
Creates a permit-to-purchase/training system for many semiautomatic firearms:
The bill targets many semiautomatic firearms that:
accept detachable magazines, and
fall into the state’s “specified semiautomatic firearm” definitions.
In practical terms, that can include many:
AR-pattern rifles
AK-pattern rifles
tactical shotguns
some pistols
Before buying covered firearms, a person generally must complete:
state-approved training,
background/vetting requirements,
and obtain eligibility approval through a sheriff process
Establishes mandatory training requirements:
The law creates different training pathways depending on eligibility/history.
The system includes:
classroom instruction,
firearm safety,
legal instruction,
and in some cases live-fire qualification.
This is why many Colorado instructors and ranges started building:
4-hour courses,
12-hour courses,
CHP crossover structures,
qualification systems,
and state-compliant curriculum tracking.
The state-approved modules and instructor requirements became a major operational component of the law.
Restricts sales/transfers of covered firearms without compliance:
FFLs/dealers generally cannot transfer covered firearms unless the purchaser:
has completed the required process,
presents proper documentation,
and meets state requirements.
So the law effectively changes covered semiautomatic firearm purchases from:
standard background-check purchase
to:
regulated eligibility purchase.
What firearms are impacted?
The truth is it’s clear as mud. The Attorney General has the power to update the SSF (Specified Semi-Automatic Firearms list at any time. The current list is 150+ pages long and even includes firearms that are specifically exempted within the text of SB3.
It’s understood traditional handguns such as those used for Concealed Carry are not impacted by this bill. It directly targets AR/AK/Sub patterned firearms generally referred to as “assault weapons”. To find out if a firearm you’re looking at falls under this list, please contact your local gun store.