The 1947 Kalashnikov AK-47 was never a new design by the Soviets but a direct descendant of the German assault rifles encountered and captured on the Eastern Front from 1942-45. The Germans tested two models of the Mkb-42 from Haenel (H) and Walther (W) which led to the former's STG-44 (aka MP-44). New development had been forbidden by Hitler for new rifles, but the false MP (submachine gun) designation allowed for the assault rifles to go forward anyway. By the time Hitler found out about it, the new rifle was so highly favored that Hitler coined the term "Assault Rifle" (Sturmgewehr) and the STG-44 was born. The Soviets captured the rifles and loved the German 7.92 x 33mm intermediate round and closely copied the German rifle's basic architecture and round in 7.62 x 39mm postwar for the AK which went on to become the best known and produced rifle in history with over 60 million made over the decades. The Soviet RPG also started out as the Pzf-200m German AT weapon design!!! During WW2, the Germans had 3 experimental assault rifles (Mkb(H), Mkb(W), STG-45) and 3 operational (STG-44, FG-42, and VG 1-5). The STG-44 became the AK series and all variants worldwide (Valmet, Galil, R-1...) while the Mauser STG-45 became the Western standard (CETME L, HK G-3, SIG STGW 57...).

STG-44: http://world.guns.ru/userfiles/images/assault/as51/mp44-1.jpg AK-47: http://world.guns.ru/userfiles/images/assault/as01/ak47_3.jpg