C.R.S. § 18-12-301

As used in this part 3, unless the context otherwise requires: (1) “Bureau” means the Colorado bureau of investigation created and existing pursuant to section 24-33.5-401 , C.R.S. (2) Intentionally left blank —Ed. (a) “Large-capacity magazine” means: (I) A fixed or detachable magazine, box, drum, feed strip, or similar device capable of accepting, or that is designed to be readily converted to accept, more than fifteen rounds of ammunition; (II) A fixed, tubular shotgun magazine that holds more than twenty-eight inches of shotgun shells, including any extension device that is attached to the magazine and holds additional shotgun shells; or (III) A nontubular, detachable magazine, box, drum, feed strip, or similar device that is capable of accepting more than eight shotgun shells when combined with a fixed magazine. (b) “Large-capacity magazine” does not mean: (I) A feeding device that has been permanently altered so that it cannot accommodate more than fifteen rounds of ammunition; (II) An attached tubular device designed to accept, and capable of operating only with, .22 caliber rimfire ammunition; or (III) A tubular magazine that is contained in a lever-action firearm.