Comparing: ISU-122S vs. M56 Scorpion

A heavy assault gun, built on the basis of the IS tank, was effective against German heavy tanks as well as fortifications. The prototype was built at the Chelyabinsk Kirov Plant in April 1944. The vehicle entered service in August of that year, and a total of 675 vehicles were manufactured in 1944 and 1945.

The M56 SPG was intended to support airborne units as a light tank destroyer that could be transported by cargo planes or inserted by parachute or glider. The vehicle was mass produced from 1953 through 1959, but it was not popular and was soon replaced by the Sheridan light tank. The Scorpion was occasionally used to provide artillery support in Vietnam.