ACP (Automatic Colt Pistol) ammunition is a rimless, straight-walled pistol cartridge made in the United States. It was developed by John Browning in 1902. This improved version of the .45 Colt cartridge has since become popular among firearms enthusiasts.
The cartridge was designed to fit in the new semi-automatic pistols being produced at the time. Such as the Colt 1911. Its original purpose was to replace the less powerful .38 Long Colt. The .32 ACP was much less powerful than the .45ACP round. Its smaller size gave it an advantage in concealable and compact pistols.
The .32 ACP is a low-pressure round that was designed for short-range self-defense. It is not capable of penetrating the same material as the .45ACP, but it is capable of penetrating skin and bone. Its terminal energy is generally much less than other handgun rounds, making it an inadequate choice for a serious self-defense situation. However, the .32 ACP is considered a useful and reliable defensive round when used in the correct weapon.
The .32 ACP is often used in pocket pistols such as the Walther PPK, the Makarov PM, and even the Beretta Tomcat