8×22mm Nambu

The 8×22mm Nambu is a bottlenecked pistol cartridge Kijirō Nambu designed around 1902 for his own Type A “Grandpa” Nambu pistol, and it went on to chamber every standard-issue Japanese military pistol through the Second World War, including the Type 14 and the Type 94. It resembles the German 7.65×21mm Parabellum in overall size and layout but is not interchangeable with it, and it carries a noticeably lower muzzle energy than contemporary Western service pistol cartridges of similar bore — a difference Allied ordnance officers remarked on when they examined captured examples during the Pacific War.

Japan issued it from 1904 until its military defeat in 1945, and captured stocks and pistols continued to see irregular use for years afterward across several Asian conflicts. It was never adopted outside Japan and its former sphere of occupation, and no commercial ammunition maker loads it today; what is available on the collector market is small-batch or historical surplus rather than a current factory product.

No free dimensional standard exists for this cartridge, so every dimension in this entry, including its one recorded load, is drawn from Wikipedia’s own uncited infobox figures and recorded as estimated rather than verified. The single FMJ load’s stated 117mm test barrel and 315 m/s muzzle velocity come from the same uncited source; ½mv² reproduces the infobox’s own published energy figure closely, which is some corroboration but not a primary citation. No ballistic coefficient is published for this cartridge.