Q. Can I legally possess a machine gun in Colorado?
A. Unlike many other states (which ban them outright), otherwise lawfully possessed Title II weapons (machine guns, suppressors, short barreled rifles and shotguns, AOW’s, and destructive devices) are legal in Colorado, but those firearms do have significant restrictions and regulations set by federal law (mostly defined in the 1934 National Firearms Act).
Colorado law prohibits possession of silencers, machine guns, short barreled shotguns and short barreled rifles. It has an exception for persons who have “a valid permit and license for possession of such weapon.” See C.R.S. section 18-12-102. While there is no state level permit or license for NFA firearms, a lawful Federal registration for such a firearm is considered to meet the requirement of this statute. This is a common structure for these laws, it puts the burden on you to show the firearm is lawfully registered, should your possession of it come to the attention of local law enforcement. If you fail to do this then your possession of it is prohibited.
18-12-102. Possessing a dangerous or illegal weapon - affirmative defense
(1) As used in this section, the term "dangerous weapon" means a firearm silencer, machine gun, short shotgun, short rifle, or ballistic knife.
(2) As used in this section, the term "illegal weapon" means a blackjack, gas gun, metallic knuckles, gravity knife, or switchblade knife.
(3) A person who knowingly possesses a dangerous weapon commits a class 5 felony. Each subsequent violation of this subsection (3) by the same person shall be a class 4 felony.
(4) A person who knowingly possesses an illegal weapon commits a class 1 misdemeanor.
(5) It shall be an affirmative defense to the charge of possessing a dangerous weapon, or to the charge of possessing an illegal weapon, that the person so accused was 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 that said person has a valid permit and license for possession of such weapon.
Colorado regulates certain items classified as destructive devices differently. Explosive and incendiary weapons (bombs and grenades for example) are also regulated under the NFA. Colorado has a fairly comprehensive scheme for regulating such weapons, and for regulating explosives in general. Private ownership of these weapons is very unusual, because they are dangerous to store and to use.
The price on machine guns is outrageous (usually 15-20 times the price of the semi-automatic counterpart). Why?
In 1986, the NRA worked to pass the McClure-Volkmer Act. Amongst other things, it halted the production of transferable machine guns in America (codified at 18 USC section 922(o). That means that if a regular person wants to buy a machine gun, he must purchase one built and registered in 1986 or earlier. Machine guns made after the law took effect are only available to government entities or in certain cases to licensed dealers, manufacturers or importers of such weapons.
Again, the NRA supported this (yet another example of the NRA selling out the American gun owner).