AKMSU

The AKMSU is the name attached to a compact carbine derived from the Soviet AKM and chambered in 7.62x39mm. For years it was thought to be a Soviet prototype made in 1959 or 1975, but evidence suggests it was never of Soviet origin and was a custom-made weapon misattributed as one. The carbine reached the British Ministry of Defence Pattern Room collection in June 1986, and when that collection closed in September 2005 it passed to the Royal Armouries in Leeds, where it remains. Several English and Russian publications documented it and the name AKMSU was attached later, yet no Russian armory documentation exists for it. Its true origin is uncertain, and it has been suspected to be a one-off Khyber Pass copy from Pakistan. It combines a Chinese-made Type 56-1 receiver with a 1977-dated AKM trunnion, a custom hand guard and a grooved custom muzzle brake whose expansion chamber is needed for the rifle to cycle correctly.