.380 ACP

A type of cartridge used in handguns for self-defense purposes. Also called 9mm Short or 9mm Kurz, this cartridge contains the same bullet (the actual projectile fired) as some of the lower-grain 9mm ammunition. The 9mm, .380 ACP, .38 Special, and even the .357 Magnum all roughly have the same bullet size; the difference lies in the length of the casing and the amount of gunpowder packed inside.

Although the .380 ACP is the least powerful of these rounds on average, it still is extremely popular as a choice for concealed carry. Because the .380 creates less pressure when fired, the typical Browning tilt-lock mechanism that separates the barrel from the frame of the gun (and moves around a little, decreasing inherent accuracy) is not needed; most .380 pistols have the barrel fixed to the frame, causing better accuracy and reducing felt recoil.

Although opponents of the .380 claim that it has little stopping power, the best rounds for the caliber (Federal Hydra-Shok, Cor-bon Pow'r ball) have approximately the same ballistics as a .38 Special. Police shooting data places these top rounds in .380 as having a 70% chance of stopping an attacker in one shot.