The Type 97 automatic cannon is a Japanese anti-tank rifle.
In need of an effective anti-tank defense for its infantrymen during the numerous border clashes with the Red Army along the Manchurian border in the mid 1930s, the Type 97 was accepted into service in 1937. Kokura Arsenal was in charge of production of these rifles until 1941, where the 20mm round was declared obsolete in tank armor penetration; at that time, only 1100 were made. In 1943, production of the rifle was restarted due to emergency war demands; this time, production was overseen by the Japanese Steel Works. Production was again halted that same year after only about 100 more were made, making a total of around 1200 rifles being manufactured.
The rifle is gas-operated and is semi-automatic, unlike most anti-tank rifles of the time. Due to it being semi-automatic, the Type 97 had an astonishingly high rate of fire when compared to other anti-tank rifles of its time, like the Boys, PzB 39, PTRD, and the PzB M.SS.41. However, with a high rate of fire came amazing recoil caused by the firing and ejection of the massive 20mm cartridge. The weapon could be lugged around by a team of two men in the field, however, a proprietary shield could be fitted to the weapon, bumping up the weight by a massive 18 kilograms. However, in spite of all of its shortcomings, the Ho-1 and Ho-3 aircraft cannons were developed from the Type 97.