In the early sixties, the Soviet leadership requested a build of machine capable of hitting any armoured enemy target from far distances. An “object 120” index and “Taran” (“Battering ram”) development code was assigned to the new self-propelled artillery unit. “Object 120” had a nine-metre gun, capable of penetrating at least 300mm of armour from 3000 metres! Partial mechanization of the reload process was implemented to ensure a high rate of fire. Moreover unlike many Soviet SPGs, "Object 120" boasted a rotating turret, had a decent enough speed (up to 63 km/h) and excellent maneuverability in general.