Type 100 submachine gun
Encyclopedia
The was a Japan
ese submachine gun
used during World War II
, and the only submachine gun produced by Japan in any quantity. It was made in two basic variants referred to by American and British observers as the Type 100/40 and the Type 100/44, the latter also known as the Type 100 (Simplified). A third variant was a folding version of the early model, sometimes referred to as the Type 100 Navy, made for parachutists.
in 1942. Japan was surprisingly late to introduce the sub-machine gun to its armed forces—a few models of the SIG Bergman 1920 (a licensed version of the German MP 18) were purchased from Switzerland in the 1920s. These were examined and copied, with significant changes. In 1942 the Type 100 SMG was first delivered for service, used by Japanese marines during the invasion of Southern China.
The Type 100 was typical of the class of simple, inexpensive, wartime submachine guns produced by all military powers—designed for maximum ease of production. It is based on a simplified Bergman MP18, modified for the 8mm Nambu round. It was an automatic-only, air-cooled, blowback
weapon firing from an open bolt and feeding from a side-mounted, 30-round detachable box magazine. The barrel was given six-groove, right-hand-twist rifling. Unusually for a submachine gun (but typical of Japanese weapons of the era), a bayonet
lug was fixed under the barrel, in this case with a heavy bar and lug. Some of these models featured a bipod
, and others featured a complicated muzzle brake
.
The Type 100 had a chrome-plated
bore to help fight corrosion in Asian jungle conditions. Its complex ammunition feed included a feature whereby the firing pin would not operate until the round was fully chambered; frequent stoppages in firing were experienced in the field. The round was the underpowered and relatively ineffective 8 mm pistol round. The curved box magazine extending from the left side made for poor weapon balance when full. The sights
were canted to the left.
for navy paratroopers.
The Type 100/40 was complex, designed with little consideration for mass production. Its sights and feed mechanism were overly complicated. Its rate of fire was some 350 to 450 rounds per minute, and it jammed frequently. The 8x22mm Nambu
pistol cartridge it fired was rather underpowered, compared to contemporary military pistol cartridges such as 9mm parabellum and .45 ACP
. In practice, the bayonet was not widely used. Some 10,000 were produced by the Kokura Arsenal for the Imperial Japanese Army
.
A folding version of this model was made for paratroops, designed with a folding stock for lighter weight. The reliability was not improved, and the folding stock proved less suited to close combat than the solid stock which stood up better in a buttstroke
. Some 6,000 to 7,500 were made at Nagoya Arsenal and delivered primarily to the Imperial Japanese Navy
for its marine paratroops (Rikusentai
), but also to Army paratroops—Teishin Shudan
—who used them in February 1942, during the Battle of Palembang, on raids against oilfields. Navy paratroops used the weapon in the first months of 1942 during the Battle of Manado
and the Battle of Timor.
The late war variant Type 100/44, the simplified model, was designed in answer to suggestions coming from field units, and to hasten production at a time when Japan was being pushed into retreat
across the Pacific Theater of Operations
—demand for submachine guns was at an all-time high. The 1944 variant was slightly longer, with simple iron sights and a greatly simplified muzzle brake consisting of two ports drilled in the barrel. The bipod and the large bayonet mounting bar were eliminated, with the bayonet fitted to the barrel instead; consequently, the muzzle protruded more from its perforated jacket. Corners were cut in production, leaving many Type 100s with roughly finished stocks and poorly welded
parts. The relatively weak 8 mm round remained the same, but the rate of fire was significantly increased, to 800 rpm. The resulting Type 100/44 was quite light, with low recoil, and demonstrated good reliability and satisfactory accuracy for close-range work. Some 8,000 were made by Nagoya Arsenal.
Despite these simplifications, Japan lacked the industrial infrastructure to produce suitable quantities of the Type 100. By 1945, only 24,000 to 27,000 had been built.
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese submachine gun
Submachine gun
A submachine gun is an automatic carbine, designed to fire pistol cartridges. It combines the automatic fire of a machine gun with the cartridge of a pistol. The submachine gun was invented during World War I , but the apex of its use was during World War II when millions of the weapon type were...
used during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, and the only submachine gun produced by Japan in any quantity. It was made in two basic variants referred to by American and British observers as the Type 100/40 and the Type 100/44, the latter also known as the Type 100 (Simplified). A third variant was a folding version of the early model, sometimes referred to as the Type 100 Navy, made for parachutists.
Design
Designed and built by the Nambu Arms Manufacturing Company under a low-priority military contract, the Type 100 was a submachine gun that was first delivered to the Imperial ArmyImperial Japanese Army
-Foundation:During the Meiji Restoration, the military forces loyal to the Emperor were samurai drawn primarily from the loyalist feudal domains of Satsuma and Chōshū...
in 1942. Japan was surprisingly late to introduce the sub-machine gun to its armed forces—a few models of the SIG Bergman 1920 (a licensed version of the German MP 18) were purchased from Switzerland in the 1920s. These were examined and copied, with significant changes. In 1942 the Type 100 SMG was first delivered for service, used by Japanese marines during the invasion of Southern China.
The Type 100 was typical of the class of simple, inexpensive, wartime submachine guns produced by all military powers—designed for maximum ease of production. It is based on a simplified Bergman MP18, modified for the 8mm Nambu round. It was an automatic-only, air-cooled, blowback
Blowback (arms)
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gases created by the ignition of the propellant charge....
weapon firing from an open bolt and feeding from a side-mounted, 30-round detachable box magazine. The barrel was given six-groove, right-hand-twist rifling. Unusually for a submachine gun (but typical of Japanese weapons of the era), a bayonet
Bayonet
A bayonet is a knife, dagger, sword, or spike-shaped weapon designed to fit in, on, over or underneath the muzzle of a rifle, musket or similar weapon, effectively turning the gun into a spear...
lug was fixed under the barrel, in this case with a heavy bar and lug. Some of these models featured a bipod
Bipod
A bipod is a support device that is similar to a tripod or monopod, but with two legs. It provides significant stability along two axes of motion .-Firearms:...
, and others featured a complicated muzzle brake
Muzzle brake
Muzzle brakes and recoil compensators are devices that are fitted to the muzzle of a firearm or cannon to redirect propellant gases with the effect of countering both recoil of the gun and unwanted rising of the barrel during rapid fire...
.
The Type 100 had a chrome-plated
Chrome plating
Chrome plating, often referred to simply as chrome, is a technique of electroplating a thin layer of chromium onto a metal object. The chromed layer can be decorative, provide corrosion resistance, ease cleaning procedures, or increase surface hardness.-Process:A component to be chrome plated will...
bore to help fight corrosion in Asian jungle conditions. Its complex ammunition feed included a feature whereby the firing pin would not operate until the round was fully chambered; frequent stoppages in firing were experienced in the field. The round was the underpowered and relatively ineffective 8 mm pistol round. The curved box magazine extending from the left side made for poor weapon balance when full. The sights
Sight (device)
A sight is a device used to assist aligning or aim weapons, surveying instruments, or other items by eye. Sights can be a simple set or system of markers that have to be aligned together as well as aligned with the target...
were canted to the left.
Versions
Two basic performance variants of the Type 100 were produced during the course of the war: the Type 100/40 was an early version with bipod and heavy bayonet lug, judged unsatisfactory because of frequent jamming of the feed mechanism, and the Type 100/44 was a simplified 1944 version that had a higher rate of fire and much greater reliability. A third variant was a lightened version of the early Type 100/40 design which was delivered with a folding stockStock (firearm)
A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks are also found on crossbows though a crossbow stock is more properly referred to as a...
for navy paratroopers.
The Type 100/40 was complex, designed with little consideration for mass production. Its sights and feed mechanism were overly complicated. Its rate of fire was some 350 to 450 rounds per minute, and it jammed frequently. The 8x22mm Nambu
8x22mm Nambu
The 8×22mm Nambu is a rimless, bottleneck handgun cartridge introduced in Japan in 1904 for the Type A Nambu pistol. It was also used in the Type 14 Nambu and Type 94 pistols, Tokyo Arsenal Model 1927, Type II machine pistol, Hino Komuro M1908 Pistol and the Type 100 submachine gun. It uses...
pistol cartridge it fired was rather underpowered, compared to contemporary military pistol cartridges such as 9mm parabellum and .45 ACP
.45 ACP
The .45 ACP , also known as the .45 Auto by C.I.P., is a cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the United States Army in 1911.-Design and history:The U.S...
. In practice, the bayonet was not widely used. Some 10,000 were produced by the Kokura Arsenal for the Imperial Japanese Army
Imperial Japanese Army
-Foundation:During the Meiji Restoration, the military forces loyal to the Emperor were samurai drawn primarily from the loyalist feudal domains of Satsuma and Chōshū...
.
A folding version of this model was made for paratroops, designed with a folding stock for lighter weight. The reliability was not improved, and the folding stock proved less suited to close combat than the solid stock which stood up better in a buttstroke
Buttstroke
The buttstroke or butt-stroking, i.e., striking someone with the buttstock of a rifle, is a common case of the use of a firearm as a blunt weapon. Buttstroke is among the major offensive techniques with the rifle and bayonet...
. Some 6,000 to 7,500 were made at Nagoya Arsenal and delivered primarily to the Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...
for its marine paratroops (Rikusentai
Japanese marine paratroopers of World War II
The Imperial Japanese Navy fielded naval paratroopers during World War II. The troops were officially part of the Special Naval Landing Forces . They came from the 1st, 2nd and 3rd Yokosuka SNLFs. The 2nd Yokosuka took no part in any airborne operations and became an island defensive base unit...
), but also to Army paratroops—Teishin Shudan
Teishin Shudan
was a Japanese special forces/airborne unit during World War II. The unit was a division-level force, and was part of the Imperial Japanese Army Air Force...
—who used them in February 1942, during the Battle of Palembang, on raids against oilfields. Navy paratroops used the weapon in the first months of 1942 during the Battle of Manado
Battle of Manado
The Battle of Manado was a battle of the Pacific Theatre of World War II. It occurred at Manado on the Minahasa peninsula on the northern part of the island of Celebes , from 11–13 January 1942 as an attempt to open a passage to attack Australia through the eastern part of Dutch East...
and the Battle of Timor.
The late war variant Type 100/44, the simplified model, was designed in answer to suggestions coming from field units, and to hasten production at a time when Japan was being pushed into retreat
Withdrawal (military)
A withdrawal is a type of military operation, generally meaning retreating forces back while maintaining contact with the enemy. A withdrawal may be undertaken as part of a general retreat, to consolidate forces, to occupy ground that is more easily defended, or to lead the enemy into an ambush...
across the Pacific Theater of Operations
Pacific Theater of Operations
The Pacific Theater of Operations was the World War II area of military activity in the Pacific Ocean and the countries bordering it, a geographic scope that reflected the operational and administrative command structures of the American forces during that period...
—demand for submachine guns was at an all-time high. The 1944 variant was slightly longer, with simple iron sights and a greatly simplified muzzle brake consisting of two ports drilled in the barrel. The bipod and the large bayonet mounting bar were eliminated, with the bayonet fitted to the barrel instead; consequently, the muzzle protruded more from its perforated jacket. Corners were cut in production, leaving many Type 100s with roughly finished stocks and poorly welded
Welding
Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...
parts. The relatively weak 8 mm round remained the same, but the rate of fire was significantly increased, to 800 rpm. The resulting Type 100/44 was quite light, with low recoil, and demonstrated good reliability and satisfactory accuracy for close-range work. Some 8,000 were made by Nagoya Arsenal.
Despite these simplifications, Japan lacked the industrial infrastructure to produce suitable quantities of the Type 100. By 1945, only 24,000 to 27,000 had been built.
Users
- Used by Chinese troops in the Korean War.: Used by North Korean troops in the Korean War.
External links
- 8 mm Submachine Gun, Type 100 (1940), Catalog of Enemy Ordnance, 1945.