8×22mm Nambu
Japanese military pistol cartridge.
Type	Pistol
Place of origin	Japan
Service history
In service	1904–1945
Used by	Japan
Wars	Russo-Japanese War World War I Second Sino-Japanese War World War II
Production history
Designer	Kijirō Nambu
Designed	1902
Specifications
Case type	Bottleneck,semi-rimmed
Bullet diameter	8.13 mm (0.320 in)
Neck diameter	8.71 mm (0.343 in)
Shoulder diameter	10.00 mm (0.394 in)
Base diameter	10.23 mm (0.403 in)
Rim diameter	10.50 mm (0.413 in)
Rim thickness	0.92 mm (0.036 in)
Case length	21.43 mm (0.844 in)
Overall length	31.56 mm (1.243 in)
Primer type	Small pistol
Ballistic performance
Bullet mass/type Velocity Energy 6.6 g (102 gr)FMJ 315 m/s (1,030 ft/s) 328 J (242 ft⋅lbf)
Test barrel length: 117 mm (4.61 in)

The8×22mm Nambu is arimless,bottleneck handgun cartridge introduced inImperial Japan in 1904, used in theType 100 submachine gun,Nambu pistols (Type A, the Type B and Type 14) and theNambu Type 94 pistol. The 8×22mm Nambu cartridge was used in both thePacific War andSecond Sino-Japanese War.

Towards the end of the 19th century, certainsemi-automatic pistol designs began to see production, such as theBorchardt C-93 andMauser C96. Japan, in the midst of theMeiji Restoration, was keen to not fall behind when it came to military technology, and devised a replacement for theirType 26revolver. By 1902, the firstNambu pistol was developed, which was chambered in 8×22mm Nambu.^[1] Initially produced for Japanese army and naval officers' private purchase, the 8×22mm Nambu was not officially adopted until 1926 when it was designated as the Type 14 pistol cartridge.^[2]

The 8×22mm Nambu round was first used in the Nambu pistols, which were first used during theRusso-Japanese War. Major usage didn't begin until theSecond Sino-Japanese War andPacific War, during which time, theType 100 submachine gun was created, which also fired 8×22mm Nambu. By the war's end in 1945, around 400,000 Nambu pistols^[3] and 8,500 Type 100s had been produced. Small batches of Nambu pistols were also exported to Siam and China before World War II.^[4][5]

After World War II, there were isolated reports of 8×22mm usage by theViet Cong during the opening stages of theVietnam War^[6] and the Chinese Communist forces in theKorean War.^[7] Afterwards there was no major demand to keep the 8×22mm round afloat, and the post-warJapan Self-Defense Forces swiftly replaced it with the9×19mm Parabellum, which during World War II was already in use in the United Kingdom and Germany. The JSDF replaced the Nambu pistol and Type 100 with theSIG Sauer P220 andMinebea PM-9, respectively.

In 1939, the cost of 8×22mm Nambu ammunition manufactured by the Imperial Japanese Army's arsenals was 390yen per 10,000 rounds.^[8] Because of the rarity and historical impact of the 8×22mm Nambu, it has become popular among post-war collectors. A box of just 15 rounds was sold in 2009 for $250.^[9]

The standard issue military 8×22mm Nambu round has a 6.6-gram (102 gr) bullet that travels at approximately 310 metres per second (1,030 ft/s) at the muzzle when fired from a Nambu pistol.^[10] The muzzle energy of the 8×22mm Nambu is half that of the9×19mm, and less than half of the7.62×25mm Tokarev,^[11] and it is often regarded as lacking in stopping power.^[12][13] However, its overallstopping power is comparable to that of the 9×17mm (.380 ACP),^[14] which was used by German and Italian officers during World War II.^[15][16]

• 8 mm caliber
• List of handgun cartridges
• List of World War II infantry weapons – Japan

• Small Arms of WWI Primer 070: Japanese Nambu Type A Modified, at C&Rsenal
• Nambu World, Original & Collectible Ammo, at Nambu World

• 8×22mm Nambu firearms
• Pistol and rifle cartridges
• Military cartridges
• World War II infantry weapons of Japan
• Weapons and ammunition introduced in 1904

• Articles with short description
• Short description matches Wikidata