>>85212149Riflemen would typically carry a loaded rifle +4-6 reloads and sub machine gunners would carry 1-2 spare drums. Because of ammunition shortages, in practice it was often far less.
Ammo weighs a lot, and soldiers had to carry everything with them as they moved. Especially in the east, a chronic shortage of trucks and vehicles meant infantry were often marching on foot, so carrying dozens of clips or ammo drums was just impractical.