9×19mm Parabellum
The 9×19mm Parabellum (also known as 9mm Parabellum, 9mm Luger, 9mm NATO or simply 9mm) is a rimless, centerfire, tapered firearms cartridge. Originally designed by Austrian firearm designer Georg Luger in 1901, it is widely considered the most popular handgun and submachine gun cartridge due to its low cost, adequate stopping power and extensive availability.