The 9×21mm

pistol A pistol is a handgun, more specifically one with the chamber integral to its gun barrel, though in common usage the two terms are often used interchangeably. The English word was introduced in , when early handguns were produced in Europe, a ...

cartridge Cartridge may refer to: Objects * Cartridge (firearms), a type of modern ammunition * ROM cartridge, a removable component in an electronic device * Cartridge (respirator), a type of filter used in respirators Other uses * Cartridge (surname), a ...

(also known as the 9×21mm IMI, 9mm IMI, 9x21mm Italian, or 9mm Italian) was designed by Jager (Loano, Italy), then adopted and commercialised by

Israel Military Industries , former_name = Israel Military Industries , type = State-owned enterprise , industry = Arms industry , fate = Acquired by Elbit Systems , successor = Elbit Systems Land , founded = , founder = , defunct = , hq_location_city = Rama ...

for those jurisdictions where military service cartridges, like the

9×19mm Parabellum The 9×19mm Parabellum (also known as 9mm Parabellum or 9mm Luger or simply 9mm) is a rimless, tapered firearms cartridge. Originally designed by Austrian firearm designer Georg Luger in 1901, it is widely considered the most popular handgun ...

, are or were illegal for civilian purchase (i.e. Italy, France, Brazil, and Mexico).

History

Based on the 9×19mm Parabellum cartridge, the case was lengthened from . The bullet sits slightly deeper in the case, which results in almost the same overall length as the 9×19mm Parabellum cartridge (). The cartridge was designed by Mr. Giordano & Mr. 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,

(IMI) started to use 9×21mm and received permission to import the UZI Defender (also called Micro Uzi) into Italy chambered for 9×21 IMI. It was the first official commercial launch for the 9×21mm. From that period on several companies in Italy started to sell 9×21mm pistols and ammunition. In just a few decades, the 9×21mm GP or 9×21 IMI became roughly 80% of the civilian small arms market in Italy.

Competition use

As it is a rimless round, the 9×21mm 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 A malfunction is a state in which something functions incorrectly or is obstructed from functioning at all. Some types of malfunctions are: *Malfunction (parachuting), malfunction of a parachute *Sexual malfunction, also called "sexual dysfuncti ...

. As other

.38 Super The .38 Super, also known as .38 Super +P, .38 Super Auto, .38 Super Automatic, .38 Super Automatic +P, or 9×23mmSR, is a pistol cartridge that fires a bullet. It was introduced in the late 1920s as a higher pressure loading of the .38 ACP, a ...

–based rimless cartridges became available, the 9×21mm decreased in popularity in the United States for competition use, but it is still widely used in many other parts of the world.

Synonyms

*9×21mm IMI *9 mm IMI *9mm Italiano *Winchester 9×21mm WIN 24-gr. bullet

Cartridge dimensions

The 9×21mm has 1.01 ml (15.5 grains H₂O) cartridge case capacity. 9×21mm maximum C.I.P. cartridge dimensions All sizes in millimeters (mm). The common

rifling In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the ...

twist rate In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pr ...

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 9×21mm case can handle up to 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.

History

Competition use

Synonyms

Cartridge dimensions

See also

References

Further reading