Developed in October and November 1941 at the Construction Bureau of the Gorky Automobile Plant under the supervision of N. A. Astrov. The vehicle came into service in January 1942, and it was mass-produced until October 1943, with a total of 8231 vehicles manufactured. Some vehicles were used until the end of the war.
Time for the successive autoreloading of each shell into the magazine.
The technical characteristics shown are for the Siege mode
Characteristics are specified for a vehicle with crew members trained to 100%.