What gun did the machine gun that the MG 3 is derived from replace?
Rheinmetall MG 3 The MG 3 is a German general-purpose machine gun chambered for the 7.62×51mm NATO cartridge. The weapon's design is derived from the World War II era MG 42 universal machine gun that fired the 7.92×57mm Mauser round.
Marder III "Marder" III was the name for a series of World War II German tank destroyers. They mounted either Soviet 76.2 mm F-22 Model 1936 divisional field guns, or German 7.5 cm PaK 40, in an open-topped fighting compartment on top of the chassis of the Panzer 38(t). They offered little protection to the crew, but added significant firepower compared to contemporary German tanks. They were in production from 1942 to 1944 and served on all fronts until the end of the war, along with the similar Marder II. The German word "Marder" means "marten" in English.