The 10mm Auto is a powerful semi-automatic pistol cartridge that was developed by Jeff Cooper and introduced in 1983 by the ammunition manufacturer, Norma. It was originally designed for the FBI as a high-velocity, flat-shooting cartridge that would offer improved stopping power over existing handgun cartridges.
The 10mm Auto cartridge fires a .40 inch (10mm) diameter bullet and has a case length of 25.2mm (0.992 inches). It is capable of producing high muzzle velocities, typically ranging from 1,100 to 1,400 feet per second (fps) depending on the load, and muzzle energies of up to 750 foot-pounds (ft-lbs). It is a versatile cartridge that can be loaded with bullets ranging from 135 to 220 grains, making it suitable for a variety of applications, including hunting, self-defense, and competition shooting.
The 10mm Auto was initially popular but saw a decline in popularity due to its high recoil and a limited selection of firearms chambered in this cartridge. However, in recent years, the popularity of the 10mm Auto has seen a resurgence due to improved firearms designs and a wider range of ammunition options. Today, the 10mm Auto is still considered a potent and effective cartridge by many shooters.