The .38 Special and .380 Automatic are two pistol cartridges that are each over 100 years old. Both of them are still quite common for self-defense purposes. While they are similar, the two cartridges are not interchangeable. A person interested in these cartridges should understand the many differences between the two.
The .38 Special uses slightly larger bullets than the .380 Auto. Bullets for the .38 Special measure .357 inches in diameter while bullets for the .380 Auto measure .355 inches in diameter. Bullets for the .38 Special are also generally heavier than those for the .380 Auto. This is due not only to the larger diameter of the .38 Special bullet, but also due to the much longer case of the .38 Special, which allows for longer bullets. Bullet weights for the .380 Auto are commonly between 85 and 95 grains while .38 Special bullets commonly weigh from 95 to 158 grains. However, some cartridge manufacturers offer lighter and heavier bullets for each.
While the bullets used in the .38 Special are larger than those used in the .380 Auto, the .38 Special will also fire the bullets faster. Again, this is due to the larger case size of the .38 Special, which allows the cartridge to use a larger amount of gun powder. Cartridge makers also load "+P" cartridges for these calibers. These cartridges use more powerful powder loads than traditional cartridges and will propel the bullets faster, with the .38 Special still offering a velocity advantage. For example, while a +P .380 Auto cartridge may fire a 90 grain bullet at just over 1,040 feet per second, a +P .38 Special cartridge may fire a larger 115 grain bullet at over 1,240 feet per second.
Energy is a mathematical calculation created by using the size and speed of an object. As the .38 Special fires a larger bullet that is moving at a higher speed, bullets from the .38 Special carry more energy than those from a .380 Auto. In the example of the .380 firing a 90 grain bullet at 1,040 feet per second, that bullet would provide about 215 foot-lbs. of energy at the muzzle. The 115 grain .38 Special bullet moving at 1,240 feet per second would produce about 395 foot-lbs. of energy at the muzzle.
One of the primary differences between the .38 Special and .380 Auto is the firearms that use these cartridges. In general, gun makers offer the smaller .380 Auto in various semiautomatic pistols, while offering the .38 Special only in revolvers. This is due mainly to the size of the cartridges but also the design of the cartridges as well as the pressure that the cartridges create when fired. Modern handguns will handle the higher pressure of the +P cartridges, while older guns should only use standard cartridges.
- ChuckHawks.com; Handgun Power Chart; Chuck Hawks
- "Catridges of the World"; Frank C. Barnes; 2000
- Shoot-N-Iron Academy; Calibers for Self-Defense; Paul W. Abel
- The Cornered Cat; Caliber Confusion; Kathy Johnson