KIS was the name of a Polish submachine gun from the time of the Second World War. It was designed and manufactured by engineers in Jan Piwnik's "Ponury" ("Grim") partisan group that was operating in Holy Cross Mountains region.[2]
The weapon was patterned after Sten, retaining its left-side magazine. Main differences were a longer barrel, with conical rear part, and lack of stock – the gun had a pistol grip instead.[3] [2]
Between November 1943 and summer 1944, a group including Polikarp Rybicki, Witold Szafranski and Stanislaw Skorupka made 37 parts kits for a simplified Sten lookalike called the KIS at a base in the Swietokrzyskie Mountains. The KIS lacked a stock and had an integral pistol grip. Unlike the Sten, it had no barrel nut. The barrel was thick at the breech end, tapering toward the muzzle.