×ばつ21mm

The ×ばつ21mm pistol cartridge (also known as the ×ばつ21mm GP, ×ばつ21mm IMI, 9mm IMI, ×ばつ21mm Italian, or 9mm Italian) was designed by Jager (Loano, Italy), then adopted and commercialised by Israel Military Industries for those jurisdictions where military service cartridges, like the ×ばつ19mm Parabellum">×ばつ19mm Parabellum, are or were illegal for civilian purchase (i.e. Italy, France, Brazil, and Mexico).

Based on the ×ばつ19mm Parabellum cartridge, the case was lengthened from 19.05 to 21.15 mm (0.750 to 0.833 in). The bullet sits slightly deeper in the case, which results in almost the same overall length as the ×ばつ19mm Parabellum cartridge (29.69 to 29.75 mm (1.169 to 1.171 in)).

The cartridge was designed by Erasmus Giordano & Armando Piscetta to be used for civil purposes with large pistols (also those designed for .45 ACP). It was named "9 mm GP". The users were not enthusiastic at the very beginning for several reasons, such as the fact that barrels had to be modified.

During the 1980s, Israel Military Industries (IMI) started to use ×ばつ21mm and received permission to import the UZI Defender (also called Micro Uzi) into Italy chambered for ×ばつ21 IMI. It was the first official commercial launch for the ×ばつ21mm. From that period on several companies in Italy started to sell ×ばつ21mm pistols and ammunition. In just a few decades, the ×ばつ21mm GP or ×ばつ21 IMI became roughly 80% of the civilian small arms market in Italy.

As it is a rimless round, the ×ばつ21mm is used in USPSA/IPSC competition in open class firearms. A rimless case is preferred because, unlike semi-rimmed or rimmed cartridges, it will not tend to lock together with other rounds in a double-column magazine, resulting in a malfunction. As other .38 Super–based rimless cartridges became available, the ×ばつ21mm decreased in popularity in the United States for competition use, but it is still widely used in many other parts of the world.

• ×ばつ21mm IMI
• 9 mm IMI
• 9mm Italiano
• Winchester ×ばつ21mm WIN [124-gr. bullet]

The ×ばつ21mm has 1.01 ml (15.5 grains H₂O) cartridge case capacity.

×ばつ21mm maximum C.I.P. cartridge dimensions^[1] All sizes in millimeters (mm).

The common rifling twist rate for this cartridge is 254 mm (1 in 10 in), 4 grooves, Ø lands = 8.79 mm, Ø grooves = 9.03 mm, land width = 3.80 mm and the primer type is small pistol.

According to the official C.I.P. (Commission Internationale Permanente pour l'épreuve des armes à feu portatives) guidelines, the ×ばつ21mm case can handle up to 235 MPa (34,100 psi) piezo pressure. In C.I.P. regulated countries every pistol cartridge combo has to be proofed at 130% of this maximum C.I.P. pressure to certify for sale to consumers.

• 9 mm caliber
• List of handgun cartridges
• List of cartridges by caliber

• "Cartuccia 9x21 GP - 9x21 Jager - 9x21 IMI". italianshooters.org (in Italian).

• Pistol and rifle cartridges
• ×ばつ21mm IMI firearms">×ばつ21mm IMI firearms
• Paramilitary cartridges

• Articles with short description
• Short description is different from Wikidata
• CS1 Italian-language sources (it)