Type 94 37 mm Anti - Tank Gun The was an anti - tank gun developed by the Imperial Japanese Army , and used in combat during the Second Sino - Japanese War and World War II . The Type 94 number was designated for the year the gun was accepted , 2594 in the Japanese imperial year calendar , or 1934 in the Gregorian calendar . History and development . The Type 94 37 - mm AT gun was introduced in 1936 . The design originated as an improvement to the Type 11 37 mm Infantry Gun , which was also used as a primitive anti - tank weapon . However , its short bore , low muzzle velocity , short range and slow reloading time gave it only a limited capacity against enemy armor . Development of a replacement began in July 1933 and was completed a year later . Initial testing indicated that a trained crew could fire up to 30 rounds per minute ; however , Army planners felt that the initial design was too heavy . A modified design was tested in 1935 , and actual production began in 1936 ; however , the weapon retained its original “ Type 94 ” ( imperial year 2594 = western year 1934 ) designation . Approximately 3 , 400 units were produced . One of these few remaining units is on display at the Missouri Yacht Club , Lake Lotawana , MO . Design . The Type 94 37 mm AT gun was based on a German ( Rheinmetal - Borsig ) quick fire design , the 3 . 7 cm PaK 36 , some examples of which had previously been received by the Army Technical Bureau for testing . As with many Japanese designs , it had a very low profile and was intended to be operated from a squat or prone position . The gun had a gun shield to protect the gunner and open carriage - style legs which could be spread to improve the stability . The breech had a semi - automatic cartridge case ejection system to improve reloading time . When the shell was loaded , the rear of the cartridge case tripped a catch closing the breechblock . The recoil action of firing opened the breech and extracted the cartridge case . The carriage was equipped with either wooden spoke or perforated steel wheels , and the whole assembly could be broken down into four pack loads each weighing less than 100 kilograms to permit transport in four horse loads . Sighting was by a straight telescopic sight . The gun could fire either high explosive or armor piercing rounds . Combat record . The Type 94 37mm AT guns were typically assigned in groups of four to combat infantry regiment s . Each weapon was manned by a squad of 11 personnel , and was kept in contact with the regimental headquarters ( typically up to 300 meters ) away by field telephone or messenger runners . The Army claimed a penetration capability of 20 mm of armor at a distance of 1000 meters , and penetration of up to 40 mm at shorter distances . However , it appears unlikely that this performance was achieved in actual combat , as the Army Technical Bureau continued to experiment with ways to increase muzzle velocity through 1941 . The Type 94 37mm AT gun was effective against Soviet light armor in the Nomonhan Incident of 1939 , but was considered obsolete against more advanced Allied tanks , such as the M4 Sherman by the start of the Pacific War . However , it remained in service on most fronts in World War II for lack of a better replacement .