Object-268

The Object-268 is a prototype Soviet tank destroyer developed from 1952 to 1956 by the Kirov factory, Leningrad, on the basis of the T-10 heavy tank. This tank destroyer was heavily armoured and featured a 152 mm M64 gun, derived from the 152mm M53 mounted on the SU-152G.

Wow that's Object-268 has good frontal armour and penetration.