The Experimental Model 2 Submachine Gun (試製二型機関短銃 Shisei-ni-gata kikan-tanjū) was a submachine gun of Japanese origin chambered in the 8mm Nambu round and was issued to Japanese Naval units. The machine gun was produced in relatively small numbers for the IJA during the invasion of Shanghai. During its trial periods it was found that the 8mm round which it used had a tendency to jam the weapon further restricting its use by both the Imperial Marines and army. After adopting several changes to the body a much smaller and lighter variant was introduced, christened the "bull pup" by American G.I.'s who encountered it in combat as it was so rare. It had a 50 round cartridge magazine extending from the pistol grip, a unique feature which would not resurface in sub machine gun design for nearly