a 90mm gun deals 320 damage (with HE)
a 180mm gun deals 1700 damage (with HE) (5* as much)
a 360mm gun woud deal 8500 damage (with HE) 5* as much)
a 75mm gun deals 175 damage with HE
a 150mm gun deals 900 damage with HE (again, almos 5x as much)
the 380mm would deal round 9500 damage (with excel and some random gun values its possible to calculate back the, damage = shell size paramater that WG uses)
9500 damage with HE is just insane much, shooting within 5m of a tank would ALWAYS mean a 1 shot kill, and its wont be able to hit for splash...
the sturmtiger is just too powerfull, the same a modern tank wouldnt hit in wot, in real live a sturmtiger can 1 shot kill a modern MBT with ease, a 380mm shell is equal to a bomb dropped by a plane, yet this ``bomb`` doesnt fall, it crashes into the building/tank/whatever with 900 km/h, just the kinetic energy would blast a tank to bits
getting hit by this shell is equal to getting hit by a truck of 50ton driving @ 110km/h, yet this shell also says BOOM, and a truck wont (and the truck is big, and a shell is small
a sturmtiger can blast any tank, be it modern or old, to bits on direct impact, and those ww2 tanks would even get crushed by a ``near`` miss...
the only way to put this tank ingame is to nerf its damage to insane low values, but even if the tank would get 50% of its real power it would be massive OP, just drive it @ Himmelsdorf to camp alley, and wait till they come, with 1 shell u will kill 5 tanks, and u have won the match....