9mm and .380 ACP cartridges - both popular choices for self-defense rounds - have the same diameter, but a 9mm round is longer. The .380 ACP round is cheaper and easier to handle and conceal, while the 9mm is more powerful overall. The rounds can both be used in revolvers and autoloaders, but are not interchangeable with one another.
The .380 ACP cartridge (also called a 9mm Browning) was introduced in 1908 by Colt as a self defense weapon. The .380 ACP cartridge is rimless and straight - walled. The 9mm (9×19mm Parabellum) cartridge was introduced in 1902 by German weapons manufacturer DWM for their Luger semi-automatic pistol.
| .380 ACP | 9mm | |
|---|---|---|
| Designer | John Browning | Georg Luger |
| Bullet Diameter | .355 in (9.0 mm) | 9.01 mm (0.355 in) |
| Case Type | Rimless, straight | Rimless, tapered |
| Neck Diameter | .373 in (9.5 mm) | 9.65 mm (0.380 in) |
| Place of Origin | United States | German Empire |
| Maximum Pressure | 21,500 psi (148 MPa) | 235.00 MPa (34,084 psi) |
| Base Diameter | .374 in (9.5 mm) | 9.93 mm (0.391 in) |
| Rim Diameter | .374 in (9.5 mm) | 9.96 mm (0.392 in) |
| Case Length | .680 in (17.3 mm) | 19.15 mm (0.754 in) |
| Overall Length | .984 in (25.0 mm) | 29.69 mm (1.169 in) |
| Velocity | 1050 FPS | 950-1400 FPS |
| Type | Pistol; Cartridge | Pistol / Revolver / Carbine / SMG / Derringer; Cartridge |
| Penetration | 9' | 8 - 40" (13') |
| Produced | 1908 | 1902 – Present |
| Used by | Primarily for self defense. Used as a backup weapon by some armed forces. |
NATO and others; Militaries, police, and self defense. |
| Variants | - | 9 mm NATO, 9×19mm Parabellum +P, 9×19mm 7N21 +P+, 9×19mm 7N31 +P+ |
| Rim Thickness | .045 in (1.1 mm) | 0.90 mm (0.035 in) |
| Land Diameter | .348 in (8.8 mm) | 8.82 mm (0.347 in) |
Power and Performance
The power of .380 ACP guns is noticeably below that of 9mm weapons. The maximum velocity (1000 FPS) and energy ratings (148 MPa) of the .380 are about 40% below a 9mm, both using JHP+P type loads. While this means the .380 is less destructive, it also performs with less of a recoil, making it a more accurate weapon in short-range, rapid-fire use.
The 9mm has a maximum velocity of 1,400 FPS and an energy rating of 2465 foot pounds, and is by all measures a more powerful cartridge. The downside of this additional power (when compared to the .380) is a stronger recoil, lowering overall accuracy in rapid-fire situations. The video below tests the performance of the .380 ACP against that of the 9mm.
Accuracy
The fact that the .380 cartridge fires with less force gives it the advantage of being more accurate, particularly in rapid - fire situations, as there is less force to contend with while attempting to keep the shots on target. In single-shot or long - range scenarios, it mostly comes down to user skill.
Penetration
The .380 has less penetration power than the 9mm round: 9 inches for the .380 versus 13 inches for the 9mm.
