World War 2 In Review

Japanese Type 1 37mm Anti-tank Gun

Soldiers examine a captured Japanese 37mm anti-tank gun, January 1945. A carrier fitted with deep wading screens passes by in the background.

The Type 1 37 mm anti-tank gun was an anti-tank gun developed by the Imperial Japanese Army and used in combat during World War II. The Type 1 number was designated for the year the gun was accepted, 2601 in the Japanese imperial year calendar, or 1941 in the Gregorian calendar.

After the Nomonhan Incident, the shortcomings of the Type 94 37 mm anti-tank gun had become obvious, and the Imperial Japanese Army started the development of a new anti-tank gun to be more effective against the new Soviet tanks. However, as a new design would take time, as an interim measure, the existing Type 94 37 mm AT gun was modified with a longer barrel to provide for greater armor penetration. As the Type 1 37 mm AT Gun, it was introduced to combat units in 1941. Approximately 2300 units were produced.

The Type 1 37 mm AT Gun was basically a Type 94 37 mm AT gun with a slightly longer gun barrel. As with the Type 94, 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. It used a semi-automatic breech block with a horizontal sliding wedge. When the gun was fired the spent shell casing was automatically ejected and upon loading a fresh shell the breech block closed automatically. A hydrospring recoil mechanism was housed under barrel. The weapon had a split trail which opened to an angle of 60 degrees for firing to improve stability. Transport was by towing behind a truck or horse, via two steel disc wheels fitted with sponge rubber filled tires.

The Type 1 37 mm AT Gun was available only in limited quantities, and the additional barrel length provided for only an incremental improvement in performance over the more numerous Type 94 37 mm AT gun. It was marginally effective against the Allied M3 Stuart light tank in the Pacific War, but not against the M4 Sherman which was soon fielded in large numbers by the Allies. It was fielded in a wide variety of areas, but most notably Southeast Asia, and continued to be used with diminishing effectiveness until the end of World War II.

Type: Anti-tank gun

Place of origin: Japan

In service: 1941–1945

Used by: Imperial Japanese Army

Wars: World War II

Designed: 1941

Number built: 2,300

Weight: 725 pounds (329 kg)

Barrel length: 1.85 m (50 calibers)

Shell: 37×254 mm. R

Caliber: 37 mm

Action: Breech loading

Elevation: -10 to +36 degrees

Muzzle velocity: 780 m/s

Maximum firing range: 6,000 meters

Sights: Straight telescope

Type 1 37mm Anti-tank Gun.

Japanese Type 97 Automatic Cannon (20mm Anti-tank Rifle)

Type 97 Automatic Cannon (20mm Anti-tank Rifle).

The Type 97 automatic cannon is a 20-millimeter (0.79 in) Japanese anti-tank rifle that began development in the 1930s. It was used by the Imperial Japanese Army (IJA) during the Second Sino-Japanese War, the Soviet–Japanese border conflicts and the Pacific War. Ever-greater thicknesses of armor on tanks rendered the Type 97 obsolete by about 1942.

Concerned by reports of Chinese purchases of Vickers 6-Ton tanks and rising tensions with the Soviet Red Army along the Manchurian border, the IJA issued a requirement for an anti-tank rifle in 1935. The Nagoya Arsenal submitted a weapon derived from their copy of the 13.2-millimeter (0.52 in) Hotchkiss M1929 machine gun while the Kokura Arsenal submitted a new design using a 20×125 mm cartridge. The first round of testing in March 1936 was not satisfactory and both guns were returned to their designers to rectify problems encountered during the trials. The Kokura Arsenal built eight prototypes for the second round of trials held at the Army Infantry School in 1937, after which the IJA rejected the Nagoya weapon. It identified several problems that needed to be fixed and a batch of fifty guns was built for operational trials in 1938. After another round of trials in December at the infantry and cavalry schools, the weapon was accepted as the Type 97 Automatic Cannon.

The gun has a gas-operated delayed-blowback mechanism in which the barrel and receiver also recoiled to help steady the weapon. Despite reports that it can fire in full-automatic mode, the weapon lacks a selector switch to distinguish between single-shot and fully automatic modes. The Type 97 was the heaviest anti-tank rifle of World War II and weighs 52 kilograms (115 lb) ready to fire, minus the gun shield, and 68 kilograms (150 lb) including the shield and four carrying handles, handily exceeding its design weight of 40 kilograms (88 lb). It uses a seven-round removable box magazine mounted above the receiver. The gun can fire a dozen rounds per minute. It has an overall length of 2.09 meters (6 ft 10 in) and the removable barrel, including the muzzle brake, was 1.065 meters (3 ft 5.9 in) (53-calibers) long.

The Type 97 fired solid-steel armor-piercing-tracer (AP-T), high-explosive-tracer and high-explosive incendiary-tracer shells. The initial AP-T round was the Type 97 and it had a softer grade of steel than the later Type 100. The 162-gram (5.7 oz) AP-T projectiles had a muzzle velocity of 790 m/s (2,600 ft/s). Based on a captured Japanese ammunition table, the Type 97 round was credited with the ability to penetrate 30 mm (1.2 in) of armor at 90° at a range of 250 meters (270 yd). The same table credited it with the ability to penetrate 9 mm (0.35 in) of armor at 2,000 meters (2,200 yd).

Production of the Type 97 began in 1939 at the Kokura Arsenal with the first of 950 that were made through 1941. Production ceased that year, although a further 100 rifles were built by the Nihon Seikosho Company in the first half of 1943. Including prototypes, a total of 1,108 rifles were manufactured. The anti-tank rifle cost ¥6,400 at a time when a normal rifle cost ¥77. Beginning in 1940, the barrels were chrome-plated to extend their lives.

The Type 97 was assigned to IJA infantry battalions, normally on the basis of a single anti-tank platoon allocated to each infantry company. Each platoon had two 11-man sections each with a single Type 97. In addition to the section leader, there were four men assigned to carry the gun, four ammunition bearers and two horse-holders for the nine horses nominally assigned to the section. Over long distances, the Type 97 was broken down into three parts to be carried by the horses.

The weapon first saw combat during the Battles of Khalkhin Gol in 1939, where it reportedly disabled a number of the lightly-armored vehicles used by the Soviets at that time. The Type 97 was not extensively deployed in China until the following year, by which time they were mostly used as infantry support weapons. Reflecting this change, most of the ammunition produced in 1941–1942 was high-explosive, not armor-piercing. The rifle was not widely deployed in the Southwest Pacific during World War II, although it was used by the Teishin Shudan paratroopers of the Imperial Japanese Army Air Force. The Type 97’s 20 mm round was no longer effective against modern tanks after 1942. The Ho-1 and Ho-3 autocannon were developed from the Type 97 for use on aircraft.

Type: Anti-tank rifle

Place of origin: Empire of Japan

Used by: Imperial Japanese Army

Wars:

Second Sino-Japanese War

Soviet–Japanese border conflicts

World War II

Designed: 1935–1938

Manufacturer: Kokura Arsenal

Unit cost: ¥6,400

Produced: 1939–1943

Number built: 1108

Weight: 52 kg (115 lb)

Length: 2.09 m (6 ft 10 in)

Barrel length: 1.065 m (3 ft 5.9 in)

Cartridge: 20×125mm

Cartridge weight: 162 g (5.7 oz)

Caliber: 20 mm (0.79 in)

Action: Gas-operated

Rate of fire: 12 rounds/min

Muzzle velocity: 790 m/s (2,600 ft/s)

Maximum firing range: 2,000 m (2,200 yd)

Feed system: 7-round box magazine

Type 97 anti-tank rifle, with magazine and carrying handles attached.

Type 97 Automatic Cannon (20mm Anti-tank Rifle).

Japanese Type 4 75mm Anti-Aircraft Gun

Japanese Type 4 75mm Anti-Aircraft Gun.

The Type 4 75 mm AA gun was an anti-aircraft gun developed by the Imperial Japanese Army, which went into production in 1943. The Type 4 number was designated for the year the gun was accepted, 2604 in the Japanese imperial year calendar, or 1944 in the Gregorian calendar. Due to the lack of raw materials available and the great damage by air raids to its industrial infrastructure, only 70 units were made. These units were retained for defense of the Japanese home islands during World War II.

In 1927, the Bofors company of Sweden had designed a new 75 mm AA gun which was purchased by the Royal Swedish Navy. This was developed into a mobile anti-aircraft gun with a wheeled carriage, which was exported to the Republic of China, Persia, and Thailand.

Japanese forces captured examples of the Bofors M29 75mm AA gun from the National Revolutionary Army of the Kuomintang government of China, and the Army Technical Bureau was impressed with its performance, which was much superior to the existing Japanese Type 88 75 mm AA Gun. By reverse engineering a close copy was designed and went into production in 1943. However, Japan lacked the raw materials and its industrial infrastructure was too damaged by air raids to follow through with mass production. Only 70 units were completed before the surrender of Japan.

The Type 5 75 mm tank gun was a variant design of the Type 4 75 mm AA gun used as the main armament on the Type 4 Chi-To medium tank.

The Type 4 75 mm AA gun had a single piece gun barrel with sliding breech, mounted on a central pedestal. The firing platform was supported by four legs, each of which had adjustable screwed foot for leveling.

Coming into service towards the end of the war, all seventy Type 4s that were operational were retained on the home islands as part of the bolstering of Japan’s defenses against Allied air raids and against the perceived threat of Allied invasion.

Type: Anti-aircraft gun

Place of origin: Japan

In service: 1944–1945

Used by: Imperial Japanese Army

Wars: World War II

Designed: 1943

Number built: 70

Weight: 5.85 tons

Barrel length: 4.23 m (13 ft 11 in) L/56.4

Caliber: 75 mm

Barrels: single

Elevation: -5 to +85 degrees

Traverse: 360 Degrees

Rate of fire: 10 rpm

Muzzle velocity: 860 m/s (2,800 ft/s)

Maximum firing range: 17,000 m (56,000 ft), 10,000 m (33,000 ft) max ceiling