"Sturmgewehr" - Haenel / Schmeisser MP 43 MP 44 Stg. 44 assault rifle
They look very similar but functionally not the same. There are videos of Mikhail Kalashnikov talking about this. He had handled the STG-44 and obviously it affected his design outwardly, but internally they aren’t the same. Kalashnikov made a much simpler and easier to produce rifle in keeping with Soviet methods at the time. It truly was brilliant in its simplicity and should be required study for mechanical engineers for the KISS method.