ball and hollowpoint .45 ACP rounds are powerful handgun ammunition.

The .45 ACP (Automatic Colt Pistol) pistol cartridge was designed by firearms designer John Browning. Based upon his earlier .380 ACP pistol cartridge, the .45 ACP was introduced along with Colt M1911 pistol adopted by the US Army in 1911. The round was later used in several submachine guns.

Design

As the M1911 was designed as a cavalry pistol, it had to be able to stop horses. The US cavalry also demanded stopping power similar to the .45 Colt cartridge (sometimes erroneously called the ".45 Long Colt"). The resulting .45 ACP cartridge is similar in performance to the .45 S&W cartridge, and thus somewhat less powerful than the .45 Colt cartridge.

Performance

The result is one of the world's most effective combat pistol cartridges, one that combines very good accuracy with ample stopping power for use against human assailants. However the .45 ACP has disadvantages as a combat round. It is a low-velocity round, and thus not effective against body armour. The rounds lack accuracy or velocity at long range. Another drawback is the bullet's large size and greater material costs in manufacturing compared to the 9 mm Luger cartridge.

Even in its full metal jacket form the .45 ACP cartridge is very effective against targets that do not wear body armour, because the large bullet has a tendency to expand when it hits bone. Hollow-point configurations increase the expansion and flesh-cutting potential of the round.

The .45 ACP bullets have little tendency to overpenetrate, which otherwise results when a projectile passes through an intended target with enough velocity to injure another person. The combination of stopping power and controlled penetration makes the .45 ACP practical for police use. Many US hostage rescue teams prefer the .45 ACP because of these qualities.

Today most of the US military uses the 9 mm Luger cartridge, but the accuracy of the .45 ACP cartridge has maintained its popularity with large caliber sport shooters, US police agencies and special forces. The US Marines still use the round with their new Heckler und Koch Mk 23 pistols.

Muzzle velocity

• 14.7 g (230 gr) Full Metal Jacket: 260 m/s (860 ft/s)
• 11.9 g (185 gr) CCI/Speer Gold Dot JHP (from 5in (127 mm) barrel): 317 m/s (1041 ft/s)
• 14.7 g (230 gr) Federal Hi-Shok JHP (from 5 in (127 mm) barrel): 260 m/s (860 ft/s)

Variants

Several manufacturers market pre-loaded .45 ACP rounds in sizes ranging from 117 to 230 grains (8 to 15 g). Specialty rounds are available in weights under 100 grains (6.5 g) and over 260 grains (16.8 g), but the most popular round among reloaders remains the original 200 grain (13 g) bullet. Combat rounds sold under such names as "Hydra-shok" are made with hollow points and partial metal jackets designed to spread upon impact with soft tissue, both increasing the energy transferred from the round to the target and enhancing the cutting power of the expanded round. Some hollow-point ACP rounds are legally available only to qualified law enforcement purchasers.

Synonyms

• .45 Auto
• 11.43 x 23 mm

Weapons using the .45 ACP

• M1911
• Thompson submachine gun
• Reising
• M3 "Grease Gun"
• MAC-10
• M16K
• De Lisle carbine sniper rifle
• FP-45 Liberator
• GLOCK 21, GLOCK 30, GLOCK 36

See also

• List of firearms
• List of handgun cartridges
• List of rifle cartridges