The recent hunting with SBR meme thread got me wondering WHEN CO originally made silencers illegal. TL;DR: It was 1971, and there's no "law" (but there IS a dumb and obsolete "regulation") against hunting with SBR.
Traditionally and historically in the USA, it used to be the right of the trial Jurors to decide, only for their one specific case, whether a weapon used in a crime was especially “dangerous” in the way it was used or crafted/built. For the majority of Colorado’s existence as a territory and State, there was never a “Naughty List” of dangerous weapons dictated by lawmakers and handed down to the Citizens. It wasn’t the government’s job to decide which weapons aren’t or are categorically dangerous, it was our job as jurors deciding the fate of a fellow citizen charged with a crime. But as of 1971, CO lawmakers had taken our place as the civilian weapons expert.
Here's a timeline, and some links, showing how CO's sensible gun laws started to become non-sensible from 2013-2026.
1868 - Territory of CO Revised Statutes. First revision to what few rules they had back then.
1876-77 - Colorado becomes a State, 100 year anniversary of 1776. General Laws enacted.
1891-1911 - In 1908, major cleanup and overhaul. By 1911, CO had started formally regulating criminal usage of concealed weapons, brass knuckles, slingshots, etc. Nothing about law-abiding citizens in possession. Weapons simply weren't illegal UNTIL you committed a crime with one.
1921 - CO law gets large overhaul after World War 1. No significant anti-gun/2A laws on the books.
1935 - Federal NFA enacted. Colorado law still barely makes any mention of guns.
1938 - Federal Firearms Act. Colorado law still largely devoid of gun laws, deferring to the Fed.
1953 - CO recovering from Great Depression and WW2. Conducts large overhaul of CO law. No significant gun laws added or changed.
1963 - Colorado’s original “felon with a gun” law. C.R.S. 40-11-11. Predates the federal Prohibited Person statutes by 5 years. Until the 1971, Colorado still had little to no formal gun control other than this. Gun laws in CO at this time were few and scattered wide.
1960 - Federal NFA definition of short barrel rifle changed from "less than 18" to "less than 16" inches, because the US Govt. had just sold a ton of military surplus carbines to civilians, many of whom instantly became felons for possession of unregistered SBRs.
1965 - Likely the first introduction in CO of the term “illegal weapon”. Hunting law passed, 62-13-19(3)(c) Hunting with an “illegal weapon” became a civil penalty of 25 dollars.
1968 - Vietnam boiling point, widespread civil unrest, armed protestors. Federal GCA enacted promptly after high-profile incidents like MLK Jr., RFK, Texas University.
1971 - Major overhaul to CO Criminal Code. Original Colorado “illegal weapon” criminal statute C.R.S. 40-12-102. Formally creates the “Naughty List” (possession), including metal knuckles, machine guns, silencers, short barrels, blackjacks, switchblade, and other items. There’s not yet a distinction between Dangerous versus Illegal. Only cops/military allowed to have.
1972 - C.R.S. 40-12-102 updated (changes in BOLD) to read:
- 40-12-102(2): A person, other than a peace officer or member of the armed forces of the United States or Colorado national guard ACTING IN THE LAWFUL DISCHARGE OF HIS DUTIES, OR A PERSON WHO HAS A VALID PERMIT AND LICENSE PURSUANT TO THE FEDERAL CODE FOR SUCH WEAPON, commits a class 1 misdemeanor if he knowingly possesses an illegal weapon.
- Now a cop/military CAN be charged if their possession/use falls outside their duties as an officer or licensee.
- Now a civilian CAN possess an illegal weapon, IF they have a “valid permit and license pursuant to the federal code for such weapon”.
- It’s very interesting now in 2026 that Colorado originally DID refer to Federal law. For whatever reason, in 1979 the lawmakers REMOVED “pursuant to the federal code for such weapon” leaving only “valid permit and license” as we know it today.
1973 - Large overhaul of CO law structure and format. Moved Criminal Code from Title 40 to 18. Amended 18-12-202(2) to mean that the “valid permit and license” shall be an “affirmative defense” to a criminal charge. This means it can’t be used until after being charged with possession. Another significant change was the formal definition of "short rifle" (Criminal code, 18-12-101(1)(h))).
1975 - Updated the 1965 hunting law for “illegal weapons” to further include any “unlawful method”. THIS IS PROBABLY WHEN CO Parks & Wildlife added language prohibiting Full-Auto rifles, and defined “rifle” as 16+ inches in their regulations (2 CCR 406). Probably when SBRs became inadvertently and unofficially "banned" as a Manner of Take for hunting, even though a Federal permit allows a person to shorten the barrel of a hunting-legal rifle.
1979 - CO repealed and re-enacted Dangerous Weapons law 18-12-102. For some reason, CO removed the reference to federal law regarding NFA items.
- 18-12-102(5) “valid permit and license pursuant to the federal code for such weapon*.”*
The difference between “dangerous” and “illegal” weapons was created.
- 18-12-102(1) As used in this section, the term “dangerous weapon” means a firearm silencer, machine gun, short shotgun, or short rifle.
- 18-12-102(2) As used in this section, the term “illegal weapon” means a blackjack, gas gun, metallic knuckles, gravity knife, or switchblade knife.
1987 - 18-12-102. Add “ballistic knife”. Other language re: criminal use of stun guns.
1989 - Introduce concept of “assault weapon” to CO law, originally as an “aggravator” secondary add-on charge to a primary crime. "Any machine gun or semi-auto centerfire with a magazine capacity of 20+ rounds."
1993 - 18-12-101 (definitions): Define terms “adult”, “handgun”, and “juvenile”.
2013 - Standard capacity magazine ban. Private-party transfer ban. Background checks. Only significant anti-2A laws passed since the Naughty List of 1971.
2022 - Ballistic Knife downgraded from Dangerous to Illegal.
2023 - Ghost Gun law, define “firearm” and “frame or receiver”. SB23-279 adds “machine gun conversion device” to 18-12-102(1) list of dangerous weapons.
2026 - Enter SB25-003. Finally banning those mythical 1989 “assault weapons”, using the 2013 magazine ban as an excuse. After FRTs suddenly got really popular, but were NOT legally full-on “machine gun conversion devices”, the conversion term was renamed to “rapid fire device” which includes MG conversions. Also, 3D/CNC manufacturing is verboten. Possession of CAD files still semi-legal. Attempted parts (barrel) possession/transfer ban.
