In 1941 about a hundred komsomolet armored tractors were upgraded and converted into open-type, self-propelled guns as vehicles by mounting long-barrelled 57mm guns on them. The new machines were given the name ZIS-30 and had entered the field by the end of September. The anti-tank guns proved excellent in fighting light and medium enemy equipment but insufficient protection of the cockpit and the high vulnerability of the crew lead to heavy losses among these SPG's in their very first outings.
For 6 more points you have a Zis 2 field gun on tracks. It has its advantage/disadvantages.
- This tank has the same armor penetration as the Zis 2 fieldgun.