SERVICE – Japanese military, Guerrilla and Revolutionary use throughout Asia into the 1960s, dependent on availability of ammunition
This was the last submachinegun produced by Imperial Japan. As it was adopted late in the war, manufacturing methods had suffered and the finish of the weapon was poor including many welds being in evidence. The original model, the Type 100, was first tested by the Imperial Army in 1939 and adopted in 1940. Low priorities and other roadblocks prevented that weapon from going in to full production until 1942. The numbers produced of all of the Type 100 submachineguns were relatively small when compared to other Japanese small arms. About 8,300 specimens of the Type 100/44 were reportedly produced before the end of WWII out of the approximately maximum of 20,000 total production of the Type 100 models.
For the Type 100/44, the weapon was simplified to both ease manufacture as well as use fewer critical materials. The cyclic rate of fire was nearly doubled from that of the two earlier patterns, intended to make it slightly easier to engage a fleeting target in the jungle. The bayonet mounting for the Type 30 bayonet was included in the Type 100/44, but it had been simplified to just being a lug mounted on the barrel jacket, the ring of the bayonet slipping over the muzzle of the submachinegun.
