The Ruger Mini-14 is a gas operated self-loading carbine introduced in 1973 and based upon the designs of John Garand. The Mini-14 is chambered for a 5.56 mm cartridge which it takes from a 5-, 10-, 20- or 40-round box magazine and fires with a muzzle velocity of 1005 meters per second to an effective range of 300 meters. The Mini-14 has a 470 m long barrel and is fitted with a bead on post foresight and an adjustable aperture rearsight. A military version, the Mini-14/20GB with a protected foresight, flash suppressor, bayonetlug and a heat resistant fibreglass hand guard was also produced. Research Mini-14