Comparing: SU-101 vs. ISU-130

In 1944 the Construction Bureau of the Ural Heavy Machinery Plant developed the SU-101 with the D-10S gun and the SU-102 with the D-25S gun. Both vehicles were designated as Uralmash-1. Prototypes were manufactured in April 1945. The vehicles never entered mass production nor saw service.

This heavy SPG on the basis of the ISU-122S was developed in 1944, with a prototype built in October. The 130-mm S-26 gun, based on the B-13 naval gun, was mounted on the ISU-122S. The vehicle underwent automotive and firing trials by 1945, but penetration characteristics were inferior to those of the 122-mm guns, and the war was drawing to a close, so the vehicle never entered service.