Type 100 Submachine Gun

Type 100 second pattern submachine gun. Tubular construction with a drilled barrel jacket that has a bayonet lug on the right side. The action is marked with 100, a Japanese character (type), the Nagoya Arsenal stamp and the serial number. It has a one piece stock that has been repaired with a wood butt plate. There is a D ring bolt on the left side to dismantle the receiver from the stock.

The Type 100 Hyaku-shiki kikantanju was a Japanese submachine gun used extensively during the Second World War and the only submachine gun produced by Japan in quantity. Designed and built by the Nambu Arms Mfg. Co., the Type 100 was a robust, if unremarkable submachine gun that was first delivered to the Japanese Imperial Army in 1942. The Type 100 was a well made gun, albeit with several strange features, including a complicated ammunition feed device that, for safety purposes, ensured that a round was completely chambered before firing, a complex system compounded by the curious bottle shaped round the Type 100 used. A bayonet lug was fixed under the barrel. Despite its shortcomings and complexities, the Type 100 featured sophisticated sights and a high quality chrome plated barrel to aid cleaning and reduce wear. Some models also featured a bipod or a complicated muzzle brake. A number of Type 100 variants were produced during the course of the war. One model included a folding stock for paratroops, although few were made as the folding stock weakened the weapon's structure in combat.

Late production models introduced in 1944 were greatly simplified in order to hasten production at a time when Japan was being pushed into retreat across the Pacific theatre and demand for submachine guns was at an all time high. The 1944 variant was slightly longer, and featured simple iron sights. Corners were cut in production, leaving many Type 100s with roughly finished stocks and poorly welded parts. Despite these simplifications, Japan lacked the industrial infrastructure to produce sufficient quantities of the Type 100. By 1945, 30,000 had been built.