The Type 92 7.7mm machine gun(九二式七粍七機銃,Kyūni-shiki nana-miri-nana kijū?) was developed for aerial use for the Imperial Japanese Navy before World War II. It was the standard hand-held machine gun in multi-place IJN aircraft during the most part of the Pacific War. It proved to be seriously inadequate. Aircraft produced in the later part of the conflict often were equipped with weapons such as Type 1 and Type 2 machine guns or Type 99 cannon.
Essentially a copy of the shroudless post-WWI aircraft-mounted version of the British Lewis gun, the Type 92 was fed with a drum magazine and used in a flexible mount. It was chambered in a Japanese copy of the .303 British cartridge. The main external difference between the two models was the trigger guard, and cooling fins around the barrel and gas piston tube. Neither the post WWI British aircraft Lewis nor the Japanese copy featured the distinctive thick barrel shroud of the original gun (although ground based versions generally retained it). It was deleted as it was found that the airflow past the aircraft was sufficient for cooling the barrel and a few pounds could be saved by simply eliminating the shroud.