Development started in 1942. In April 1943 the General Motors company produced the first prototypes. One of a few American tank destroyers manufactured on its original chassis, not on a tank chassis. The tank destroyer became the fastest armored vehicle, of this type, of World War II. A total of 2,507 vehicles were produced from July 1943 through October 1944.
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%.