The Gewehr 43 is seen used by the Germans on a few episodes. These rifles were the German’s efforts at a semi-automatic rifle to combat the rise of semi-automatic fire power by the Russians and the Allied forces.
In the series, the Germans are often seen being outgunned by the Americans due to having to use the standard Army issue Mauser Karabiner Kar 98, bolt action rifles which were slow and limited to 5 rounds before having to reload. This was verses the the M1 Garand, which was capable of rapidly firing 8 rounds and also reloading was very fast.
The Germans needed a semi-automatic firing rifle and they made efforts to put these Gewehr 43 into service, of which some 400,000 were made. It may seem like a lot but compared to the amount of M1 Garands put into service of some 1.6 Million, this number was relatively small.