SU-152 "Taran"

The Object 120 SU-152 "Taran" (СУ-152 «Таран») was a fully enclosed Soviet tank destroyer built in 1965, which never progressed past the experimental stage.

History
In the early 1960s, the Soviet military concluded that the armor-piercing ammunition used by the T-55 medium tank, and the T-10 heavy tank was unable to penetrate the frontal armor of the newest American M60 and British Chieftain main battle tanks. The Soviets, therefore, began parallel research on several different anti-tank weapon systems, such as the development of new armour-piercing discarding sabot and shaped charge ammunition for existing tank guns, new rifled and smoothbore tank guns with calibers ranging from 115 mm to 130 mm with anti-tank missiles.

One of these projects became the SU-152 "Taran". The factory designation was Object 120 (Объект 120). In terms of firepower and mobility, it surpassed all foreign tank destroyers. The main reason the SU-152 "Taran" wasn't adopted was due to the development and adoption of more effective 125 mm smoothbore tank gun and anti-tank missiles.

Armament
The SU-152 "Taran" was armed with the 152.4 mm M-69 "Taran" rifled gun, with a barrel length of 9,045 mm, fitted with a powerful muzzle brake. With an overall length of about 10 meters, it is the longest gun of any type ever installed in a fully enclosed armoured fighting vehicle. The gun had a maximum direct fire range of 2,050 meters. The SU-152 "Taran" carried 22 rounds of APDS and high-explosive ammunition. The gun had a semi-automatic breech block, with a rate of fire of 3–5 rounds/min. The high-explosive ammunition had a 43.5 kg shell and a maximum charge of 10.7 kg. Firing the 12.5 kg APDS shell with a maximum charge (10.7 kg), which gave it a muzzle velocity of 1,720 m/s, the M-69 "Taran" had an armor penetration of 290 mm of RHA at 90° at a range of 2,000 meters.