What is ACP Ammunition?

ACP stands for “Automatic Colt Pistol,” a designation used for various pistol cartridges developed by the legendary American firearms designer John Moses Browning in collaboration with the Colt’s Patent Firearms Manufacturing Company. ACP ammunition is associated with semi-automatic pistols and submachine guns, with the cartridges designed specifically to function reliably in these types of firearms.

Some of the most well-known ACP cartridges include:

  • .25 ACP (6.35x16mm) – Introduced in 1905, this small cartridge is used primarily in pocket pistols and has low recoil, making it easy to handle for self-defense situations. However, it is considered underpowered compared to more modern self-defense cartridges.
  • .32 ACP (7.65x17mm) – Introduced in 1899, this cartridge gained popularity in Europe and was used in numerous compact semi-automatic pistols. It offers moderate power and low recoil, making it suitable for self-defense and target shooting, though it has been largely supplanted by more powerful cartridges.
  • .380 ACP (9x17mm) – Introduced in 1908, this cartridge is also known as the 9mm Short or 9mm Kurz. It is a popular choice for compact and subcompact pistols due to its balance of power, size, and moderate recoil. The .380 ACP is widely used for self-defense and concealed carry applications.
  • .45 ACP (11.43x23mm) – Introduced in 1904, this is one of the most iconic and widely-used pistol cartridges in the United States. Developed for use in the Colt M1911 semi-automatic pistol, the .45 ACP is known for its stopping power and effectiveness in self-defense and military applications. The cartridge remains popular among law enforcement, military, and civilian shooters.

ACP ammunition is generally characterized by its rimless, straight-walled case design and its use in semi-automatic pistols and submachine guns. These cartridges continue to be popular for self-defense, law enforcement, military, and recreational shooting applications.