The 7×20mm Nambu is a

rimless A rim is an external flange that is machined, cast, molded, stamped, or pressed around the bottom of a firearms cartridge. Thus, rimmed cartridges are sometimes called "flanged" cartridges. Almost all cartridges feature an extractor or headspacing ...

, bottleneck handgun cartridge designed in

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

for use in the Type B or "Baby" model

Nambu pistol are a series of semi-automatic pistols produced by the Japanese company Koishikawa Arsenal, later known as the Tokyo Artillery Arsenal.Hogg, Ian, ''Pistols of the World 4th Edition'' (2004) p. 191. The series has three variants, the Type A, the ...

. The cartridge is a scaled-down version of the

8×22mm Nambu The 8×22mm Nambu is a rim (firearms), rimless, cartridge (firearm), bottleneck handgun cartridge introduced in Imperial Japan in 1904, used in the Type 100 submachine gun and Nambu pistol. The 8×22mm round was used during the Pacific War and Sec ...

used in all other Nambu pistol models. It has a muzzle energy more than a

.25 ACP The .25 ACP ( Automatic Colt Pistol) (6.35×16mmSR) is a semi-rimmed, straight-walled centerfire pistol cartridge introduced by John Browning John Moses Browning (January 23, 1855 – November 26, 1926) was an American firearm designe ...

and close to the

.32 ACP .32 ACP ( Automatic Colt Pistol, also known as .32 Automatic) is a centerfire pistol cartridge. It is a semi-rimmed, straight-walled cartridge developed by firearms designer John Browning, initially for use in the FN M1900 semi-automatic pi ...

References

* The Hand Cannons of Imperial Japan, Derby, H., 1981, Taylor Publishing Company, ISBN 0-940424-00-2 * The Weapons Series no. 5 THE BABY NAMBU Japanese 7-mm. Pistol, Marsh, Roger, 1946, Pub. by the author. Pistol and rifle cartridges Military cartridges World War II infantry weapons of Japan {{ammo-stub