9×21mm

The 9×21mm pistol cartridge (also known as the 9×21mm IMI or 9 mm IMI) was designed by Israel Military Industries for those markets where military service cartridges, like the 9×19mm Parabellum, are banned by law for civilian use in Italy.

History
Based on the 9×19mm Parabellum cartridge, the casing was lengthened from 19.05 to 21.15 mm. The bullet sits slightly deeper in the casing, which results in almost the same overall length as the 9×19mm Parabellum cartridge (29.69 to 29.75 mm).

Synonyms

 * 9×21mm IMI
 * 9 mm IMI

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 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 9×21mm case can handle up to 235 MPa 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.