Development of the A-20 tank started at Kharkov Factory No. 138 in December 1937. The project was a further development of the BT-7 tank and became a predecessor of the legendary T-34. Work on the vehicle was led by Mikhail Koshkin. On May 18, 1938, technical characteristics of the tank designated BT-20 were approved. Only a few experimental prototypes, with a wheeled caterpillar suspension, were built for training purposes.
Time for the successive autoreloading of each shell into the magazine.
Characteristics are specified for Siege 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%.