A firearm is generally a rifle, pistol, shotgun, or other portable weapon that expels a projectile (bullet) by use of an explosive action. The definition of a firearm may vary from state to state under state statutes—and under federal statutes—and related items such as a muffler or silencer may be included in the definition of a firearm for purposes of certain criminal offenses (crimes).
In Colorado, a firearm is defined under state law as any pistol, revolver, rifle, or shotgun designed to be fired by the use of a single hand. The definition also includes any other weapon, device, instrument, material, or substance, whether animate or inanimate, that is capable of producing death or serious bodily injury, and which operates on the principle of an explosive or other propellant. Colorado law aligns with federal law in that it includes silencers and mufflers as part of the definition of a firearm in certain contexts, particularly in relation to criminal offenses. It's important to note that both state and federal laws regulate the possession, sale, and transfer of firearms, as well as the possession of accessories like silencers. These regulations are subject to change, so it's advisable to consult with an attorney or review the most current statutes for up-to-date information.