In the context of firearms, "ACP" stands for "Automatic Colt Pistol." This designation describes a series of cartridges originally designed by John Browning for use in semi-automatic pistols, notably featuring a straight-walled case and a combination of a designed powder charge tailored for 1911-type pistols.
Key Definitions and Background:
Origin: The ACP designation was first introduced with the .45 ACP cartridge, which was adopted by the U.S. Army in 1911 for use in the Colt M1911 pistol. The design was innovative, allowing for a reliable feeding and ejection system in semi-automatic firearms.
Cartridge Design: ACP cartridges generally have a rimless, straight-walled design, which helps in feeding from magazines. They are designed to be fired from semi-automatic pistols rather than revolvers.
Popularity: The .45 ACP is one of the most recognized ACP cartridges, known for its stopping power and use in both military and civilian applications. Other notable ACP cartridges include the .30 ACP (used in the 1910 Colt) and the .40 ACP, which was a later development intended to offer a higher velocity and energy round than the .45 ACP while maintaining manageable recoil.
Common ACP Cartridges:
- .45 ACP: A large-caliber cartridge favored for self-defense, law enforcement, and military use.
- .40 S&W: Often associated with law enforcement, a compromise between the stopping power of the .45 ACP and the higher capacity of 9mm.
- .380 ACP: A smaller caliber often used in compact and subcompact pistols for concealed carry.
Associated Handguns: The ACP cartridges are often associated with various models of semi-automatic handguns, especially the Colt M1911 and variants. Other manufacturers, such as Glock, Sig Sauer, and Smith & Wesson, also produce firearms chambered in these cartridges.
- Performance: ACP cartridges are generally known for their moderate to heavy bullet weights and slower velocities compared to some other semi-automatic cartridges, leading to higher recoil but significant stopping power.
In summary, "ACP" refers to a series of semi-automatic pistol cartridges developed by Colt that have become widely used in a variety of firearms, known for their reliability and effectiveness.