The Soviet ISU-122S was an improved version of the ISU-122 heavy self-propelled gun, introduced in 1944 to increase rate of fire and combat efficiency. It mounted the 122mm D-25S gun, the same weapon used on the IS-2 heavy tank, which featured a semi-automatic breech mechanism. This allowed the crew to achieve a faster rate of fire—up to 4–5 rounds per minute compared to the slower ISU-122. Armour remained formidable, with up to 120mm of frontal protection, while mobility was provided by the V-2-IS 12-cylinder diesel engine, giving a top speed of about 37 km/h (23 mph). Like its predecessor, the ISU-122S was capable of destroying German heavy tanks such as the Tiger II at long range while also excelling in the assault gun role with powerful high-explosive shells. It entered combat in late 1944, taking part in Soviet offensives into Eastern Europe and during the Battle of Berlin, where it was particularly valuable in urban fighting. Though produced in smaller numbers than the standard ISU-122, the ISU-122S was considered a superior design and helped set the stage for the Soviet doctrine of heavy assault guns in the post-war years.
 
Multi part resin model.
 
Printed by Imperator Models on License from Wargame 3D.