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.