Prohibited Firearms in Colorado
Colorado law outlines strict rules on which firearms are legal to possess and which are classified as prohibited weapons. These restrictions are designed to prevent the circulation of firearms deemed especially dangerous to public safety. Possession, sale, or use of prohibited firearms is a serious offense that can lead to felony charges, prison time, and permanent loss of firearm rights.
Prohibited Firearms Defense Lawyer in Colorado
If you’ve been charged with possessing or using a prohibited firearm, the consequences can be life-changing. A conviction may not only result in incarceration and heavy fines but can also permanently strip you of your right to own or carry firearms in the future.
The Law Office of Matthew A. Martin, P.C. has extensive experience representing individuals accused of weapons and firearm crimes in Colorado. Attorney Martin knows how prosecutors handle prohibited weapons cases and how to challenge questionable evidence or unlawful police procedures.
Call (303) 725-0017 today to schedule a confidential consultation. The firm represents clients in Denver, Arapahoe County, Adams County, Jefferson County, Douglas County, Boulder County, and Broomfield County.
Information Center
Definition of Prohibited Firearms
Under C.R.S. § 18-12-102, prohibited firearms include weapons that are restricted due to their design, destructive capability, or concealability. These typically include:
- Short-barreled shotguns (barrel less than 18 inches or overall length under 26 inches).
- Short-barreled rifles (barrel less than 16 inches or overall length under 26 inches).
- Firearm silencers or suppressors (unless federally licensed).
- Machine guns or fully automatic firearms.
- Ballistic knives (knives that project blades using a spring or explosive charge).
Owning, transporting, or manufacturing any of these weapons is illegal in Colorado unless you have proper federal authorization.
Examples of Conduct That Could Lead to Charges
- Modifying a rifle to reduce its barrel length below the legal minimum.
- Purchasing a suppressor online without proper licensing and bringing it into Colorado.
- Possessing an antique fully automatic weapon without federal clearance.
- Transporting a sawed-off shotgun in a vehicle.
Types of Prohibited Firearms in Colorado
Colorado law bans several categories of firearms due to their destructive potential, concealability, or ability to rapidly cause harm. Each type presents unique dangers that lawmakers have determined justify strict regulation.
Short-Barreled Shotguns – Short-barreled shotguns, often referred to as “sawed-off shotguns,” are shotguns with barrels under 18 inches or an overall length under 26 inches. The danger with these weapons is their ease of concealment and devastating close-range firepower. Unlike standard shotguns designed for hunting or sport, sawed-off versions spread pellets widely and unpredictably, making them especially lethal in crowded or close-quarters environments. Because of their concealability and destructive potential, they are often associated with violent crimes.
Short-Barreled Rifles – Short-barreled rifles are rifles with a barrel shorter than 16 inches or an overall length under 26 inches. These weapons are dangerous for similar reasons as sawed-off shotguns, they can be concealed more easily than a traditional rifle but still maintain high velocity and accuracy at short ranges. This makes them particularly concerning to law enforcement, as they can be carried discreetly yet deliver rifle-caliber rounds.
Firearm Silencers or Suppressors – Colorado prohibits silencers or suppressors unless the owner has the appropriate federal ATF registration. The main concern is that suppressors allow criminals to mask the sound of gunfire, making it harder for police or bystanders to respond quickly. While suppressors do not make guns completely silent, they significantly reduce the noise and muzzle flash, which can embolden unlawful use and complicate investigations.
Machine Guns (Fully Automatic Firearms) – Machine guns are firearms capable of firing multiple rounds with a single trigger pull. These are considered some of the most dangerous weapons because they allow a shooter to rapidly fire dozens or even hundreds of rounds in seconds. The potential for mass casualties is extraordinarily high, which is why both state and federal law heavily restrict these weapons. Only individuals with special federal licenses may legally possess them.
Ballistic Knives – Although not technically firearms, ballistic knives are included in the statute. They are knives that launch blades through a spring or explosive mechanism. These weapons are outlawed because of their unpredictability, ability to inflict lethal damage at short range, and their association with concealed attacks.
Exceptions to Prohibited Firearm Laws in Colorado
Although Colorado law criminalizes possession of certain firearms, there are limited exceptions where individuals may legally own or use these weapons. These exceptions are tightly controlled and usually require federal authorization in addition to compliance with state law.
Federal Registration and Licensing – Certain prohibited firearms, such as short-barreled rifles, short-barreled shotguns, silencers, and machine guns, may be legally possessed if the owner complies with the National Firearms Act (NFA). This process requires:
- Filing an application with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF).
- Passing a background check and fingerprinting.
- Paying a federal tax stamp (usually $200).
- Registering the weapon with the federal government.
Without these federal authorizations, possession remains a felony under both federal and Colorado law.
Law Enforcement and Military Exceptions – Law enforcement agencies and members of the U.S. military may lawfully possess and use prohibited firearms in the course of their official duties. For example, SWAT teams may deploy short-barreled rifles or fully automatic weapons during high-risk operations. These exemptions do not apply to officers or service members in their personal capacity.
Antique or Curio and Relic Firearms – Some older firearms classified as antiques or designated “curios and relics” under federal law may fall outside the scope of Colorado’s prohibitions. For example, a historically significant machine gun from World War II might be legally possessed if it is properly registered under federal law and kept as a collectible rather than an active-use weapon.
Licensed Dealers and Manufacturers – Federal Firearms License (FFL) holders with special occupational tax status (SOT) may lawfully manufacture, transfer, or possess prohibited firearms for sale to law enforcement, military, or other authorized parties. These entities are heavily regulated and must maintain strict compliance with record-keeping, storage, and transfer laws.
Penalties and Aggravating Circumstances
Class 5 Felony – Most prohibited firearm offenses are charged at this level, punishable by 1–3 years in prison and fines of up to $100,000.
Class 4 Felony – Repeat offenders or cases involving trafficking multiple prohibited firearms may face higher charges, carrying 2–6 years in prison and fines up to $500,000.
Aggravating Factors
- Possession of prohibited firearms during the commission of another felony.
- Connection to organized crime or trafficking operations.
- Use of a prohibited firearm in the commission of a violent act.
Defense Strategies
- Lack of Knowledge – The defense may argue that the accused did not know the firearm was modified in a way that made it prohibited.
- Federal Authorization – Certain individuals with federal permits (e.g., collectors, dealers, or manufacturers) may legally own otherwise prohibited firearms.
- Improper Search and Seizure – If law enforcement obtained the firearm without a valid warrant or probable cause, the evidence may be suppressed.
- Weapon Misidentification – Not all modified firearms meet the legal definition of prohibited weapons. Expert testimony can challenge the classification.
Frequently Asked Questions
What counts as a short-barreled rifle in Colorado?
Any rifle with a barrel shorter than 16 inches or an overall length under 26 inches is considered prohibited.
Can I own a suppressor in Colorado?
Not unless you have proper federal authorization. Without ATF registration and approval, silencers are illegal under state law.
What happens if I inherit a prohibited firearm?
Even if obtained innocently, possession without the proper federal license is illegal. The firearm must be surrendered or legally registered.
Can a prohibited firearm charge be reduced?
Depending on the circumstances, an attorney may negotiate to reduce the charge to unlawful possession of a weapon, which carries lighter penalties.
Additional Resources
Colorado Revised Statutes – Prohibited Use of Weapons (C.R.S. § 18-12-102) – Official state law defining prohibited firearms and weapons.
Colorado State Patrol – Guidance on firearm regulations and restrictions across Colorado.
Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) – Federal rules on restricted firearms, silencers, and machine guns.
Prohibited Firearm Defense Lawyer in Colorado
A prohibited firearm charge is one of the most serious weapons offenses under Colorado law. You cannot afford to face these accusations without skilled legal counsel. The Law Office of Matthew A. Martin, P.C. provides aggressive and knowledgeable defense for individuals charged with weapons and firearm crimes throughout Colorado.
Call (303) 725-0017 today to discuss your case and start building your defense.