Type 100/40 and 100/44
Type: Japanese sub-machine gun.
History: Sub-machine gun development in Japan was curiously neglected until about 1935, after which an experimental model was produced and tested. But there appears to have been little enthusiasm for the weapon, which, considering that Japan was by then engaged in a war with China and preparing for war throughout the East, is most surprising. The sub-machine gun would have been an ideal weapon for them, and the thought of the Japanese Army armed with a cheap and simple sub-machine gun such as the Russian PPSh is quite terrifying; the combat in the Far East would have been a good deal more bloody, and one or two touch-and-go affairs might well have gone the other way.
The Type 100, Model 1940, was issued in 1941-42 in limited numbers. It was a modified Swiss Solothurn S1-100, which was also used by the German and Axis armies in Europe. Although far from perfect its performance was good enough to stimulate interest in the weapon, and this led to development of an improved version, the Model 1944, but work began too late and was carried out too slowly to allow stocks to be built up.
The Model 40 came in two patterns, one for infantry use with a solid stock and one for Airborne troops using a hinged folding stock. Both were fitted with bayonet bars under the barrel, and the interior of the barrels was chrome plated. The infantry models were sometimes fitted with a small bipod. Mechanically there was little of note; they were simple blowback weapons working on familiar principles.
The only recorded use of these weapons in combat was in the Japanese parachute attack on the Dutch oilfields in Java in 1942, when they were reported to have been highly effective. There is no record of their appearance against US forces in the South Pacific nor against British troops in Burma. It is believed that less than 10,000 of both models were produced.
Variant:
Type 100/44: Mechanically the same as the 100/40, this had a weaker recoil spring which increased the rate of fire to 800 rpm. The bayonet bar was removed and bayonet attachment was by two lugs on the barrel casing. The muzzle was formed into a compensator by drilling two lateral holes. There were other small changes intended to make the weapon easier to manufacture. It is reported that about 7,000 were made in the last year of the war, but none of them appear to have reached the hands of troops.
Users: Japan (for all variants).

Japanes Marine with a bullet-proof vest and a Type 100 sub-machine gun.
|
Type 100 |
| Type |
Sub-machine gun |
| Caliber |
8 mm |
| Length |
35.0 in |
| Weight |
8 lb 8 oz |
| Barrel |
9.0 in long, 6 grooves, right hand twist |
| Feed system |
30-round detachable box magazine
|
| System of operation |
Blowback, selective fire |
| Muzzle velocity |
1,099 feet/sec |
| Rate of fire |
450 rpm
(Model 100/44 800 rpm) |
| Manufactures |
Atsuta Ordonance Factory, Nagoya Arsenal |
| Production delivery |
1941 |
| Final delivery |
1945 |
| Production figure |
approx. 17,000
(7,000 of Type 100/44 in 1945) |
| Price per unit |
?
(not designed for ease of production) |

3d model of Japanese sub-machine gun Type 100/40.

The Japanese Type 100/40 with bayonet bar.

The Type 100/44 was not designed for ease of production there were never enough to meet the demands.
|