Newcomers to the world of guns and ammo generally have tons of questions. Even those of us who grew up in the culture can be confused by all the gun lingo and alphabet soup acronyms. One of those common questions is, “What does ACP stand for?”
Although we may often see those three letters, not everyone knows exactly what they mean. The short answer? ACP stands for “Automatic Colt Pistol.”
The longer answer? The letters “ACP” are used to denote various cartridges designed by John Browning for Colt semi-automatic pistols. These straight-sided cartridges are all similar in appearance and include .25 ACP, .32 ACP, .38 ACP, .380 ACP, and .45 ACP.