Interesting as the 152 and Bummbar are both 6 inch artillery
How does the either compare to the 152 howitzer damage/AOE because in theory I think that's the same gun
Or maybe when they put a ZIS into an SU76 they extract it's mojo and install that into the ISU-152 when they put the 152 in there
There is a bit more to the gun then just caliber, like barrel length, ammo type used ect.
For reference-Sherman uses 75mm gun and panther use 75mm gun. Rest of the story is pretty obvious.
Same case here.
In ISU and SU-76 case, both use exactly the same weapons as their stationary counterparts, ISU uses exactly the same ML-20 howitzer, SU-76 uses exactly the same ZiS-3 gun that T2 AT gun is. Stats are different for balance reasons.