Lower ammo reserve, lower rate of fire, slightly higher base DMG.
The main difference is that it is classified as semi rifle. And thus can be used by classes other than assaulters (for example engineers or AT gunners).
Unlike StG, since that’s classified as assault rifle.
In terms of ammunition capacity, it really deserves the BR II, and there are other toggle versions in Germany, one of which is the Stendebach model 1936 automatic rifle, and the second is the Walter model 1918 shotgun
