The .380 ACP (Automatic Colt Pistol) and .38 Special are two distinct handgun cartridges that differ in terms of their history, dimensions, and typical areas of use. Here are the primary differences between the two:

1. History and Origin:

   • .380 ACP: The .380 ACP, also known as 9mm Short, was developed by John Moses Browning in 1908 for use in the Colt Model 1908 pocket pistol. It was designed as a self-defense cartridge for semi-automatic pistols.
   • .38 Special: The .38 Special was introduced by Smith & Wesson in 1898 as a successor to the .38 Long Colt. It was initially designed for use in revolvers, specifically the S&W Model 10 (formerly known as the .38 Hand Ejector).

2. Dimensions:

   • .380 ACP: The .380 ACP bullet diameter is typically 9mm, and the cartridge has a case length of 17.3mm. It operates at relatively low pressures.
   • .38 Special: The .38 Special bullet diameter is usually .357 inches (or 9.07mm), and the cartridge has a case length of 29.3mm. It operates at higher pressures compared to the .380 ACP.

3. Type of Firearm:

   • .380 ACP: The .380 ACP is predominantly used in semi-automatic pistols, which are often chosen for concealed carry due to their compactness.
   • .38 Special: The .38 Special is primarily used in revolvers, including both snub-nose and longer-barreled models. It is commonly utilized by law enforcement, self-defense practitioners, and target shooters.

4. Performance:

   • .380 ACP: The .380 ACP is considered a moderate recoil cartridge, offering lower muzzle energy compared to the .38 Special. It is generally used for self-defense at close ranges and is known for its manageable recoil.
   • .38 Special: The .38 Special has a more powerful recoil compared to the .380 ACP and offers a broader range of bullet options, including heavier projectiles. It has a well-established reputation for self-defense purposes and is also used in target shooting and competition.

It's worth noting that both cartridges have different applications and are not interchangeable due to variations in dimensions and pressure. Always consult the specifications and recommendations provided by firearm and ammunition manufacturers to ensure safe and proper usage.