Development started in the spring of 1942. After trials in the fall of 1942, the decision was made to replace the 57-mm gun with a 75-mm gun. Two prototypes were manufactured. The vehicle saw neither mass production nor service.
Time for the successive autoreloading of each shell into the magazine.
Characteristics are specified for Siege mode.
The technical characteristics are displayed for the charged turbine mode.
Characteristics are specified for Rapid mode.
Reload time of the first and second guns on double-barreled vehicles.
Characteristics are specified for vehicles with crews trained to 100%.