5.6×39mm firearms

thumb|A photo of the TKB-022PM TKB-022PM No. 1 (ТКБ-022ПМ № 1), TKB-022PM No. 2 (ТКБ-022ПМ № 2) and TKB-022PM5 No. 1 (ТКБ-022ПМ5 № 1) were Soviet bullpup assault rifles, capable of fully automatic fire, chambered for the 7.62×39mm round (TKB-022PM No. 1 and TKB-022PM No. 2) and the 5.6×39mm round (TKB-022PM5 No. 1), developed by the small arms designer German A. Korobov in the 1960s.

semi-automatic rifle

The 5.6×39mm, also known in the U.S. as .220 Russian, is a cartridge developed in 1961 for deer hunting in the USSR. It fires a 5.6mm projectile from necked down 7.62×39mm brass. While it originally re-used 7.62x39 cases, once it became popular enough commercial ammunition started being manufactured, both in the USSR and in Finland. When it was introduced to the United States by SAKO it was stamped .220 Russian. Lapua later changed the designation to .220 Russian for the American market as well.