Buying a Gun in Colorado

21 for all firearms. 'It is unlawful for a person who is less than twenty-one years of age to purchase a firearm' (class 2 misdemeanor), and a licensed dealer may not sell to anyone under 21 (class 1 misdemeanor). Exceptions: active-duty U.S. armed forces members on duty, on-duty peace officers, and P.O.S.T.-certified individuals; antiques and curios or relics are excluded. Possession: a person under 18 may not knowingly possess a handgun (class 2 misdemeanor; class 5 felony for a second offense), with exceptions for safety courses, target ranges, organized competitions, licensed hunting, travel to these with an unloaded handgun, and property of a parent, guardian or grandparent with permission.

Yes, universal. Since July 1, 2013, before any person who is not a licensed dealer transfers or attempts to transfer a firearm, the transferor must have a licensed gun dealer run a Colorado Bureau of Investigation background check on the transferee and obtain CBI approval; the dealer records the transfer as if selling from its inventory. Dealers may not transfer a firearm until CBI approves the transfer.

3 days for all firearms: a seller, including a licensed dealer, may not deliver a firearm until the later of three days after the dealer initiated the required background check, or CBI approval of the transfer. Violation is a civil infraction with a $500 fine ($500 to $5,000 for repeat offenses). Exceptions include antiques and curios or relics, certain sales to family by service members deploying abroad within 30 days, and transfers that need no background check. Local governments may adopt their own waiting periods.

A person may not knowingly possess or transport, or sell, offer to sell, transfer or purchase, an unfinished frame or receiver, or knowingly possess, purchase, transport or receive a firearm, frame or receiver that is not imprinted with a serial number by a federal firearms licensee, with exceptions for licensed importers and manufacturers and for taking a firearm to a licensee to be serialized. Colorado also makes unlawful three-dimensional printing of a firearm or firearm component a separate offense.