This is the Sturmgewehr (StG.) 44, 7.92x33 mm Kurz . Made in 1944. Initial development started in 1942 as an intermediate weapon between a bolt action rifle and a sub machine gun .
Army studies had shown that few combat engagements occurred at more than 300 metres (330 yd) and the majority within 200 metres (220 yd). Full-power rifle cartridges were excessive for most uses for the average soldier.
This development was halted by Hitler to prioritise sub machine gun production. During the invasion of the Soviet Union development was restarted under the mp43 designation. Its advantages ensured its production as the Sturmgewehr 44.
Like the AK 47 it is made mostly of stamped steel so reduce weight, manufacturing time and cost. It fired at 500 rounds per minute from a 30 round box magazine . Effective range was 300 m on automatic and 600 m on semi automatic .