Another big cat.

[CINDERS]

A heavy hitter the Russian ISU 152mm assault gun it's primary role was destruction of fortifications though it also doubles as an AT weapon and did pose a serious adversary to the Tiger 1 & Tiger II's.
Though the 2 piece ammunition and the weight of each round @48 kilo's for the projectile the rate of fire was pretty low that being said the Tiger II's L71/88mm gun and the Jagdtiger's 128mm guns proved a serious threat to the ISU series.
(See chart it lists the ISU 122mm)

*I understand the rendering of the weapons on the vehicles they could have at least put the hole near the breech end underneath so it's not that noticeable.

[browningautorifle]

*I understand the rendering of the weapons on the vehicles they could have at least put the hole near the breech end underneath so it's not that noticeable.

You could also put a false plate over it, just tin and paint...and a spot of wire feed to hold it.