5. Antitank and Infantry Guns | Section II: Infantry Weapons | Chapter IX: Weapons | TM-E 30-480: Handbook on Japanese Military Forces, Technical Manual, U.S. War Department, October 1, 1944 (Lone Sentry)

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5. ANTITANK AND INFANTRY GUNS. a. General. (1) The Japanese infantry is comparatively well armed. The first effort to give heavy weapons to the infantry was in 1921-1922, when the model 10 (1921) 50-mm grenade discharger, the model 10 (1921) 70-mm mortar, and the model 11 (1922) 37-mm gun were introduced. These three weapons were later replaced by the model 89 (1929) 50-mm grenade discharger, the model 92 (1932) 70-mm battalion howitzer, and the model 94 (1934) 37-mm gun. However, in some areas the older weapons are still in use.

(2) In 1936, the model 41 (1908) 75-mm mountain gun was replaced by a newer weapon in the mountain (pack) artillery units. The model 41 gun then was issued four to each infantry regiment and is known as the regimental gun. This move gave the infantry a lightweight 75-mm weapon of its own.

(3) When first issued, model 11 (1922) 37-mm gun was no doubt intended in part for an antitank role, although it could not be considered a threat today. Its successor, model 94 (1934) 37mm gun, has a much higher velocity.

(4) It was not until 1937, however, that the Japanese produced a purely antitank weapon. Model 97 (1937) 20-mm antitank rifle is a hard-hitting mobile weapon. Model 98 (1938) 20-mm antiaircraft antitank machine cannon can also be used against tanks.

(5) With the appearance of model 1 (1941) 47-mm gun, a modern, mobile, high-velocity weapon, Japanese antitank weapons take on a much more serious aspect.

(6) The fact that model 41 (1908) 75-mm infantry gun is provided with armor-piercing, high-explosive and hollow charge AP ammunition must be borne in mind, because this gun is so widely distributed in the Japanese Army.

(7) Japanese infantry must be considered well supplied with heavy weapons; the Army is primarily an infantry army, and the weapons of the infantry have always been the first consideration of the military.

b. Model 97 (1937) 20-mm antitank rifle. (1) General description. This is actually a single purpose, selective full or semi-automatic gas operated, antitank automatic cannon (fig. 209). Infantry can maneuver it in any sort of terrain. Two men can carry it, since it weighs but 150 pounds complete with shield and carrying handles, and it is easy to hide because of its low silhouette (16 1/2 inches without the shield). However, its sights do not permit accurate laying for the longer ranges, and tracking is difficult because traversing must be accomplished by shoulder control. In addition, the weapon has a very violent recoil. The Japanese markings

which mean "97 Model" appear on the top of the receiver.

Caliber		20-mm (0.79 inch).
Muzzle velocity		2,500 feet per second.
Weight		Gun itself—120 pounds.
		With shield and carrying handles—150 pounds.
Length (without handles)		82.5 inches.
Traverse (total)		1,600 mils (90°).
Sights:
Front		Blade type.
Rear		Peep-sight controlled by "click" drum graduated from 0 to 1,000 meters in 100 meter graduation.
Type feed		7 round box magazine.
Rate of fire		12 rounds per minute (semiautomatic).

(3) Ammunition. Armor piercing tracer and high explosive tracer ammunition has been recovered.

c. Model 98 (1938) 20-mm antiaircraft antitank automatic cannon. (1) General description. This is a gas-operated, semi- or full-automatic, all purpose weapon (fig. 210), similar in mechanism, but larger and heavier than the model 97, 20-mm antitank rifle. The ammunition is not interchangeable. The carriage permits firing from its wheels. Supported on outriggers with wheels removed it has a fast 360° traverse.

Caliber		20-mm (0.79 inch).
Type feed		20 round box magazine.
Weight		836 pounds (without wheels).
Maximum range—horizontal		5,450 yards.
Maximum range—vertical		12,000 feet.
Muzzle velocity		2,720 feet per second.
Rate of fire		120 rounds per minute.
Traverse		6,400 mils (360°).
Principle of operation		Gas-operated, semi-or full automatic.

(3) Ammunition. High explosive tracer and armor piercing tracer have been recovered.

d. Model 11 (1922) 37-mm gun. (1) General description. This weapon (fig. 211) is still in use in some areas, although its place in the infantry organization has been taken by model 94 (1934) 37-mm gun and other antitank weapons. It resembles the U.S. 37-mm infantry gun, M 1916. The gun is carried by four men. This weapon is listed by the Japanese as

which is translated "11th year model low trajectory infantry gun".

Caliber		37-mm (1.46 inch).
Weight in action		205.75 pounds.
Length (with trails folded)		90 inches.
Over-all width (in firing position)		49.25 inches.
Breechblock		Vertical sliding wedge, which may be operated semiautomatically.
Traverse		584 mils (33°) by handwheel.
Elevation		248 mils (14°) by handwheel.
Depression		85 mils (-4.8°).
Sight		Telescopic, used for direct laying.

e. Model 94 (1934) 37-mm gun. (1) General description. This weapon (fig. 212) is referred to by the Japanese as the "Infantry rapid fire gun." It is an infantry close support weapon firing both high explosive and armor piercing high explosive ammunition. It has a semiautomatic, horizontal, sliding type breechblock. When the shell is loaded, the rear of the cartridge case trips a catch that closes the breechblock. Recoil action of firing opens the breech and extracts the cartridge case. Sighting is by a straight telescopic sight. This weapon has marked on the barrel the following

which reads "94 model 37-mm gun."

Caliber		37-mm (1.46 inch).
Length (over-all in travelling position)		114 inches.
Width (over-all in travelling position)		47 inches.
Weight		714 pounds.
Traverse		1,062 mils (60°).
Elevation		+480 mils (27°).
Maximum range		5,000 yards.
Muzzle velocity (armor piercing ammunition)		2,300 feet per second.

Note. This piece may be found mounted on wooden spoke wheels or with perforated steel disc wheels as illustrated in figure 212.

f. Model 1 (1941) 47-mm gun. (1) General description. This is an antitank weapon of modern design (fig. 213). The wheels are independently sprung, and a lock is provided on each wheel for locking the springs out of action. It has a semiautomatic, horizontal, sliding wedge breech mechanism. The low silhouette, wide tread, and long split trails give this gun excellent stability. Preliminary tests indicate a muzzle velocity of 2,700 feet per second. The steel disc wheels are fitted with sponge rubber filled tires. This weapon has marked on its breech the following symbols

which mean "Model 1 47-mm mobile gun."

Caliber		47-mm (1.85 inch).
Weight		1,600 pounds.
Traverse		60°.
Elevation		+19°.
Depression		-11°.
Muzzle velocity		2,700 feet per second.

(3) Ammunition. Armor piercing high explosive and standard high explosive shells have been recovered.

g. Model 92 (1932) 70-mm howitzer (Battalion gun). (1) General description. This weapon (fig. 214), despite its unusual appearance, has proved to be effective as an infantry support howitzer. It has an interrupted thread type, drop breechblock mechanism. Light in weight and maneuverable, it fires a projectile of relatively large weight, and can deliver fire at ranges varying from 110 yards to 3,000 yards. The Japanese markings

which read "92 model infantry gun", appear on the barrel.

Figure 214. Photograph of model 92 (1932) 70-mm howitzer (Bn. gun) showing gunner and sights.

Caliber		70-mm (2.76 inch).
Total weight in action		468 pounds.
Thickness of armor shield		0.156 inch.
Traverse		800 mils (45° total).
Elevation		+50°
Depression		-10°
Range		3,075 yards.
Danger area of burst		40 yards (approximately).

(3) Ammunition. The ammunition is semifixed, the propelling charge being divided into four increments. High explosive, armor piercing, and smoke shells are fired. The standard model 88 delay and instantaneous fuzes are used.

h. Model 41 (1908) 75-mm infantry gun. (1) General description. This weapon (fig. 215) was originally the standard pack artillery weapon, but when it was largely superseded by the Model 94 (1934) 75-mm mountain (pack) gun, it was then used as an infantry "regimental" gun. It is widely distributed throughout the Japanese Army. It has an interrupted screw type breechblock and a hydrospring recoil mechanism. There are no equalizers or equilibrators. The markings

which appear on the barrel, mean "41 model mountain gun." This weapon may be easily and quickly disassembled for pack into loads, the maximum weight of each being approximately 200 pounds. Actual firing of the weapon at a range of 3,200 yards resulted in 75 percent of the rounds falling in a rectangle 20 by 30 yards. At maximum range (7,800 yards) 75 percent of the rounds fell within a rectangle 100 yards wide and 200 yards long.

Figure 215. Side view of model 41 (1908) 75-mm infantry gun, showing unusual trail construction.

Caliber		75-mm (2.95 inch).
Length (over-all)		170 inches.
Width (over-all)		48 inches.
Weight		1,200 pounds.
Traverse (total)		106 mils (6°).
Elevation		+650 mils (+40°).
Depression		-319 mils (-18°).
Maximum range		7,800 yards.

(3) Ammunition. Ammunition recovered included common high explosive, armor piercing, high explosive, shrapnel, hollow charge AP and incendiary. For description of incendiary shell see chapter 9, section V.