Type 94 75 mm Mountain Gun

The Type 94 75 mm Mountain Gun (九四式山砲) was a mountain gun used as a general purpose infantry support gun by the Imperial Japanese Army during the Second Sino-Japanese War and World War II. It superseded the Type 41 75 mm Mountain Gun to become the standard pack artillery piece of Japanese infantry divisions. It was superior to Type 41 in range and in weight. 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
Combat experience with the Type 41 Mountain Gun during the invasion of Manchuria indicated to the Imperial Japanese Army General Staff that the existing primary mountain gun lacked not only in firepower and accuracy, but also was not as easily transportable under difficult terrain as had been hoped. The Army Technical Bureau was assigned a project to develop a replacement in 1931. The first prototype was tested in 1932, and the design released for production by September 1934 as the "Type 94". However, plans to re-equip all artillery regiments with the new weapon were continually postponed due to budgetary priorities.

Design
The Type 94 75 mm mountain gun had a single piece gun barrel with sliding breechblock based on German Krupp designs and a long split-trail carriage with a hydro-pneumatic recoil mechanism based on French Schneider designs. The crew was partially protected by a gun shield made of 1/8-inch (3 mm) thick armor plate.

For so light a weapon, it embodies a remarkable number of modern construction features. It has a Schneider type, hydropneumatic independent recoil system, a Krupp type horizontal sliding-wedge breechblock, split trails with spade plates for stabilizers, pintle traverse, and an equalizing arrangement which gives it three-point suspension. Since it is trunnioned at the center of balance, it does not require equilibrators. It can be fired with trails closed or open.

The design was modular in construction, and the gun could be broken down into eleven modules within three to five minutes for transport by animals or men. The heaviest module weighed 210 pounds (95 kg), and the weapon was intended to be transported by six pack horses, or 18 men (although during the Bougainville campaign because of the tough terrain it was carried by 41 men doubtless because of the extremely difficult terrain). The gun could be reassembled within ten minutes and disassembled in from 3 to 5 minutes. At night, after the parts are rubbed with luminous bark, the same operations can be performed, although 5 to 10 minutes longer are required.

It fires the same projectiles as other 75-mm pieces and has a cartridge case identical in length with that used in the Model 38. This case is longer than that used in the Model 41 mountain gun. This is necessary because the propelling charge used in Model 94 ammunition is less than that used in the ammunition for Model 38, and firing the latter ammunition from Model 94 would damage the gun. Lack of a howitzer trajectory and of varying charges increases the dead space for the Model 94 when it fires in mountainous terrain, and the counterrecoil is said to be so slow when the piece is fired at elevations above 30° that, rather than fire above that elevation, the battery displaces forward.

Ammunition

 * High-explosive
 * M94 6 kg with 0.8 kg of TNT and M88 impact or delay fuse.
 * "A" 6.46 kg with Picric acid and dinitro and M3 combination fuse.
 * "B" 6.6 kg with 0.66 kg of Picric acid and dinitro and M88 impact or delay fuse.
 * M90/97 6.18 kg with 0.42 kg of TNT and M88 impact or delay fuse.
 * M90 Pointed HE 6.35 kg with TNT and M88 impact or delay fuse.
 * Armor piercing
 * M95 APHE 6.2 kg with 0.45 kg of picric acid and dinitro M95 small AP base fuse.
 * Shrapnel
 * M90 Shrapnel 7 kg with 0.1 kg of black powder with M5 combination fuse.
 * M38 Shrapnel 6.83 kg with 0.1 kg of black powder with M3 combination fuse.
 * Chemical
 * Star
 * M90 Illumination 5.65 kg with M5 combination fuse.
 * Incendiary
 * M90 Incendiary 6.93 kg with black powder and M5 combination fuse.
 * Smoke
 * M90 Smoke 5.73 kg with 0.1 kg of picric acid and dinitro with M88 impact fuse.

Combat record
Type 94 75 mm Mountain Gun was used extensively in Manchukuo during the Pacification of Manchukuo, and during the Second Sino-Japanese War. It was also assigned to units in the Southern Expeditionary Army and was sited in defensive positions on islands throughout the Netherlands East Indies and the South Pacific Mandate. It was one of the most common weapons encountered by Allied forces towards the closing stages of the war.

Chinese copies of the Type 94 were used by the North Koreans during the Korean War.