Ah the Sturmgewehr!
Welp,It reminded me of this weapon whose rechambered variant is still in service,named Maschinegewehr 42 (Machine-Gun '42) or simply,MG42
Maschinegewehr 42,often nicknamed as 'Hitler's Buzzsaw'
MG3 KSW,rechambered and modernised variant of WW2 era MG42,in 7.62 x 51mm...