The Type 97 automatic cannon (九七式自動砲 Kyū-nana Shiki Jidō-hō) was a Japanese anti-tank rifle produced by Kokura Arsenal.
History[]
The Type 97 anti-tank rifle was developed in response to a commission from the Japanese Army Engineering Division in 1935. It was designed at Kokura Arsenal and was trialed against a rival 13mm design from Nagoya Arsenal in March 1936, with a Steyr-Solothurn S18-100 being used as a test control. The initial trials were inconclusive, so further trials were arranged for 1937 and the Type 97 won out, predominantly on account of its 20mm chambering. Kokura Arsenal were granted a budget to improve the rifle, with minor modifications being made to the build quality of the weapon, including a strengthened receiver, trigger, and bipod. A pilot batch of 8 Type 97s was produced that year, and a further 50 in 1938. After final trials in December 1938, the decision was made to accept the Type 97 into full military service.
1,008 Type 97s were manufactured from 1939 to 1941, before production temporarily ceased. In September 1943, the Nippon Special Steel Company produced 100 more units to meet wartime demand. This was to be the last batch that was ever made, as the gun was phased out of service during the latter years of World War II due to its high cost, heavy weight, and ineffectiveness against armored tanks. Most later issue was with high-explosive rather than AP ammunition, with the gun being used in an infantry support role.
Design[]
The Type 97 is a crew-served semi-automatic 20mm anti-tank rifle, similar to the Lahti L-39 and Solothurn S18 in both application and overall size.
The rifle is gas-operated, feeding from an overhead 7-round detachable box magazine. Average rate of fire in combat for a trained crew was around 12 rounds per minute. While there were wartime reports of the gun being fully automatic, it is generally believed these were either malfunctioning guns or examples of the Type 98, a select-fire derivative: the Type 97 only has a safe-fire selector switch.
The weapon could be lugged around by a team of two men in the field: it was moved using two sets of detachable handles that allowed it to be carried like a stretcher. A splinter shield could be fitted to the weapon to protect the crew, bumping up the weight by another 18 kilograms. The Ho-1 and Ho-3 aircraft cannons were developed from the Type 97.
Unlike the aformentioned Lahti and Solothurn guns, the Type 97 only had a straight-pull charging handle which provided no mechanical advantage. This resulted in a gun that was notoriously difficult to cock, often requiring the gunner to use both hands.