The .45 ACP caliber (for Automatic Colt Pistol) was developed by John Moses Browning in 1905 and is a popular cartridge for government agencies, especially abroad, although it has since been largely superseded by the 9 x 19 caliber, which is lighter and less expensive.
The muzzle velocity of the .45 ACP is 230 - 350 m/s, which is below the speed of sound, which with a silencer allows almost silent shooting even without subsonic ammunition. This fact still makes the cartridge popular with special forces.
Due to the low muzzle velocity, gas pressure of 1300 bar or less and bullet energy of 300 - 730 joules, the caliber makes pleasant to shoot. Although the penetration is low, it has a high man stopping power.
For hunting use, the cartridge does not play a role.
Alternative designations are .45 Auto, .45 Automatic Colt and Automatic Colt pistol cal. 11.43 mm.