A further development of the O-I with improved anti-tank guns. The military command's plan was to improve the earlier models and achieve a higher level of armor protection on the vehicle. Existed only in blueprints. No finished prototypes were built and the vehicle never saw action.
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%.