sentences:  The 57 mm main gun, designed for infantry support, was a carry over from the 1933 Type 89 medium tank.The gun was a short barrelled weapon with a relatively low muzzle velocity, which was sufficient for supporting the infantry.However, in 1939 during the Battle of Khalkhin Gol (Nomonhan) against Soviet BT Tanks, the gun proved to be insufficient against the Soviet armor, causing the Japanese Army to have heavy tank losses.