Hardware and ammunition

Firearm technologies have advanced significantly in the last several decades, which has prompted state laws and regulations regarding firearm hardware and ammunition. Colorado law bans selling, transferring, and possessing high-capacity magazines. Additionally, beginning in 2024, state law also  makes it unlawful to possess a firearm, frame, or receiver without a serial number to address the use of so-called “ghost guns.”

In Colorado, local governments may pass bans on selling certain kinds of hardware and ammunition. Denver, Vail, and Boulder each have city-specific ordinances that ban semi-automatic rifles with detachable magazines

Applicable State Laws

Colorado Revised Statutes (C.R.S.) are posted on the Colorado Legal Resources Public Access Website.


Unserialized Firearms and Firearm Components: C.R.S §18-12-111.5 (SB 23-279)

  • Effective Date: June 2, 2023.
  • Current owners of unserialized firearms or components (“ghost guns”) have until January 1, 2024, to have firearms and components imprinted with a serial number.
  • The following are prohibited for unfinished firearm frames or receivers without a serial number:  
    • Possessing or transporting.
    • Selling, transferring, or purchasing.
    • Manufacturing.
    • Engaging in any of the above actions is unlawful and is classified as a Class 1 misdemeanor, except for a second or subsequent offense, which is a Class 5 felony.
    • Individuals who currently own a firearm, frame, or receiver that they personally manufactured and which lacks a serial number from a federal firearms licensee must have it imprinted with a serial number by January 1, 2024.
    • The law restricts the CBI from approving the transfer of a firearm to a person convicted of a misdemeanor violation within the past five years. Individuals convicted of the felony are prohibited from possessing firearms or other weapons.
    • Federal firearms licensees can imprint a serial number on firearms, frames, or receivers. The law establishes a process and requirements for licensees to serialize firearms.
    • Additionally, the law defines machine gun conversion devices, often called switches, as dangerous weapons. 

Prohibiting Large-Capacity Ammunition Magazines : C.R.S §18-12-301 (HB 13-1224)

  • Prohibits the sale, transfer, or possession of an ammunition-feeding device that is capable of accepting, or that can be readily converted to accept, more than ten rounds of ammunition or more than five shotgun shells (large-capacity magazine).