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380 vs. 9mm: Which Caliber is Best? preview image
Jul 30 2023
7 min read

380 vs. 9mm: Which Caliber is Best?


380 ACP is an often overlooked cartridge these days. Only a few years older than 9mm Parabellum, it filled the gap between 32 ACP and 45 ACP in the first half of the 1950s in the United States.

9mm, on the other hand, has become almost ubiquitous worldwide. It is significantly more powerful than 380 ACP, is less expensive, and has more guns in that caliber to choose from. Why would you want to get a 380 vs. a 9mm?

380 ACP fills a niche that 9mm can’t. Keep reading to learn all about the key features of these venerable cartridges!

380 ACP Overview


The 380 ACP cartridge was designed by John Moses Browning in 1908. Its performance placed it in between Browning’s other famous calibers, the 32 ACP and 45 ACP. The first handgun introduced for 380 ACP was the Colt Model 1908 Pocket Hammerless, the more powerful cousin of the 1903 Pocket Hammerless in 32 ACP.

Browning designed the round to be about the most powerful he could go while retaining a simple blowback recoil system for his pistols. Higher power rounds, like 45 ACP and 9mm Parabellum, need a barrel locking mechanism to manage recoil. This leads to a more complicated design.

380 acp - fmj - sb - 2
380 ACP Full Metal Jacket. Source:

9mm Parabellum Overview

Federal 9mm luger 124 gr

The 9mm Parabellum cartridge was designed by Georg Luger in 1901 and initially used in his namesake pistol, the P08 Luger. It was slowly adopted by different militaries in the 1940s and 1950s, eventually becoming the standard round for NATO in 1955 and the US military in 1985.

380 ACP and 9mm share the same bullet diameter, but 9mm is longer and heavier, along with having a longer case. Because the diameters are the same, 380 ACP is also called 9mm Short, 9mm Kurz, 9mm Corto, or 9mm Browning.

Diameter is where the similarities end. 9mm is significantly more powerful than 380 ACP and has become the most popular handgun caliber in the world.

9 mm
L to R: 9mm cast lead, 9mm FMJ, 9mm JHP

Specification Chart for 380 ACP and 9mm Parabellum

Specifications380 ACP9MM Parabellum
Bullet diameter0.355 in (9.01 mm)0.355 in (9.01 mm)
Neck diameter0.373 in (9.5 mm)0.380 in (9.65 mm)
Base diameter0.374 in (9.5 mm)0.391 in (9.93 mm)
Rim diameter0.374 in (9.5 mm)0.392 in (9.96 mm)
Rim thickness0.045 in (1.1 mm)0.050 in (1.27 mm)
Case length0.680 in (17.3 mm)0.754 in (19.15 mm)
Overall length0.984 in (25.0 mm)1.169 in (29.69 mm)
Muzzle energy203 ft-lbf (95 gr Federal FMJ @ 980 ft/s)364 ft-lbf (124 gr Federal FMJ @ 1150 ft/s)
Top: 9mmx19 Parabellum Bottom: 380 ACP. Source: US Concealed Carry

Key Differences Between 380 ACP and 9mm Parabellum


The chart shows us that 9mm ammo is almost twice as powerful as 380 ACP with standard loads. When it comes to hollow point bullets, there is an energy sweet spot. Too little energy, and the round fails to expand. Too much energy and the petals fold backward, reducing expansion.

9mm exists in that sweet spot, and jacketed hollow point ammo works very well with it.

380 ACP, on the other hand, has marginal energy for expansion. With the right ammunition you can get reliable expansion, but not all JHP ammo does and it is often dependent on muzzle length. A 380 ACP JHP bullet might expand reliably in a full-frame pistol, but the same bullet might not expand when fired from a pocket pistol.

Pistol Design Characteristics

380 ACP is less powerful than 9mm, so it has less recoil. 380 pistols can use simple blowback designs with fixed barrels. This reduces cost and complexity. A barrel that’s fixed to the frame can be more accurate too.

9mm, due to its power, needs to have a barrel locking system to manage recoil. This can take the form of a tilting barrel mechanism, a rotating barrel, or something else. Either way, it’s a more complicated system than a blowback design and can increase cost and complexity.

It’s interesting to note that while 380 is a smaller cartridge than 9mm, few high-capacity 380 pistols have been built. The most common high capacity 380 designs feature 12-13 rounds vs. 9mm pistols, often with 17-18 round magazines from the factory.

It seems the reason is because of the time period the pistols evolved in. Double-stack pistols didn’t start becoming popular until the latter half of the 20th Century, well after the popularity of 9mm was established. Gun makers focused their large-frame pistol designs around 9mm, leaving 380 in the lurch.


Even though it’s fallen from favor, it doesn’t mean 380 doesn’t have its uses. One thing 9mm isn’t good at is pocket pistols. It’s simply too large and too powerful of a round to be used in small pistols.

Yes, there are compact 9mm pistols out there, but nothing that’s a true pocket pistol. This is where 380 excels. The small cartridge size and lower power of the round make it ideal for these kinds of guns.

Several micro pistols have been released in recent years, such as the Ruger LCP and Smith & Wesson Bodyguard, that use the 380 ACP round. These still offer good stopping power while being extremely light and concealable with manageable recoil.

While you may not feel comfortable carrying a dinky pistol daily, you can always carry a 9mm as your primary. Stick a small 380 in your pocket or ankle holster for added peace of mind and never feel under-gunned.

S and w bodyguard
Smith and Wesson Bodyguard 380

380 ACP Pros & Cons

  • Less recoil than 9mm
  • Fixed barrel construction aids in accuracy
  • Blowback designs are simpler than locked breech designs
  • Can be used with micro pistols
  • Much less muzzle energy than 9mm
  • Unreliable hollow point expansion
  • Fewer pistols to choose from
  • Lack of high capacity pistol options
  • More expensive ammunition

9mm Parabellum Pros & Cons

  • Much more powerful than 380 ACP
  • Many more 9mm pistol designs to choose from
  • Cheaper and larger variety of ammunition
  • Available with high capacity magazine designs
  • More recoil than 380 ACP
  • 9mm is not suitable for micro pistols
  • Locked breech/tilting barrel 9mm designs can be less accurate
  • Less concealable than 380 ACP pistols


Is a .380 enough to stop an attacker?

The answer is: of course. The question about stopping power will never go away, but lots of people have been killed by rounds that are smaller and less powerful than 380. It might not have the range of 9mm, but a 380 to the chest will definitely ruin someone’s day.

What hits harder, 9mm or 380?

9mm Parabellum hits harder than 380 ACP. Typical muzzle energy for 9mm is in the 360 ft-lbf range, whereas 380 is in the 200 ft-lbf range.

Is a 380 as powerful as a 38 special?

In general, no. Although some 380 loads beat 38 special, with standard ammo, the edge goes to 38 special. It shoots a heavier bullet at the same speed as 380, so the muzzle energy will be greater.


9mm Parabellum is the world’s most popular handgun cartridge, and not for nothing. It has good power and is available for use in a large variety of pistols. It is the standard caliber for NATO and has been popular with police departments and civilian shooters across the country since the 1980s.

380 ACP has been around nearly as long as 9mm has but hasn’t been as widely adopted. It’s a smaller cartridge than 9mm and significantly weaker, but it does fill a niche these days. It is an ideal cartridge for backup guns and micro pistols, offering adequate self-defense power and concealability.

So if you’re looking for a small handgun for deep concealment, don’t rule out a 380 ACP pistol.

Written by Joel Nordness
Joel Nordness photo Joel grew up in the cornfields of Illinois. After college, he had a brief stint in California, befriending veterans at the Navy base he worked at who introduced him to shooting. Realizing how much fun shooting could be, he carried that passion with him to his new home in Indiana, where he developed a love for rare and unusual handguns and firearm history. He tries his best to keep his gun collection to reasonable levels while doing what he can to introduce new shooters to the joy of the hobby.


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