"The experimental IS tank with a 122 mm gun (IS-3) is built on the base of the IS tank and differs from it in armament. Instead of the 85 mm D-5 gun, the 122 mm D-25 gun is used, the most powerful of all currently known foreign or domestic tank guns.
The D-25 has the ballistics of the model 1931/37 A-19 corps gun.
Characteristics of the D-25 gun
- Muzzle velocity: 800 m/s
- Shell mass: 25 kg
- Muzzle energy: 833 ton-meters*
- Caliber: 121.92 mm
- Barrel length: 47 calibers
- Maximum recoil length: 550 mm
- Armour piercing
- High explosive fragmentation
- Concrete piercing