Functionally identical to 9mm Luger but with a 2mm longer case — developed specifically for the Italian civilian market where ownership of military-caliber cartridges (9x19mm NATO) is restricted. Dimensionally incompatible with 9mm Luger chambers by design.
Type: Pistol
Introduced: 1980, Israel
Parent case: 9x19mm Parabellum
Standardization: CIP
Bullet diameter: 0.355" (9.02 mm)
Case length: 0.83" (21.08 mm)
Overall length: 1.16" (29.46 mm)
Max pressure: 34,000 PSI
Rim type: Rimless
Primer: Small Pistol
Typical twist rate: 1:10
Muzzle velocity: 1150–1280 fps
Muzzle energy: 363–450 ft-lbs
Effective range: 50 yd
Common bullet weights: 124, 147 gr
Primary use: Self Defense, Competition
Production status: Active
Also known as: 9mm IMI · 9x21mm · 9×21mm
History: Developed by Israeli Military Industries for the Italian civilian sporting and self-defense market in the early 1980s. Italian law restricts civilian ownership of calibers in active military use, meaning standard 9mm Luger is effectively banned for civilians. The 9x21mm's 2mm longer case makes it legally distinct while delivering identical performance. It became Italy's primary civilian 9mm…
Notable firearms: CZ 75, Tanfoglio GT27, Various Italian-market 9mm pistols
Military use: Italy (civilian/LE market)
Similar cartridges: 9mm Luger, 9mm Largo, 9x23mm Winchester