“All’s fair ...” I suppose.
We stole the Germans machine gun MG 42 (the M-60) while the Huns stole our bazooka (`Panzerschrek’) and the Soviet T-34 tank design for their Panther tank.
My understanding has been that the M60 was based on the FG 42.
The amount of ballistic and mechanical cross-pollination that begat the modern "assault rifle" is sort of fascinating to read about. The intermediate caliber idea went back a lot further than most people would think, and another Russian (Federov) may have been the more original thinker compared to Kalashnikov.
Mr. niteowl77