Compared: The .327 Federal Magnum and .380 ACP

By Chuck Hawks

The .380 Automatic Colt Pistol was introduced in 1908 as the most powerful cartridge that could be chambered in a blow-back pocket pistol. It rapidly became a commercial success, popular with civilians for concealed carry and, particularly in Europe, with police. In Europe, the .380 is commonly known as the 9mm Kurz (9mm short) or 9x17mm Browning.

One of the most enduring pistols chambered in .380 is the German Walther PP (police pistol). This seminal and much imitated DA/SA autoloader of the 1930's was followed by the chopped PPK (Police Pistol Kurz) for concealed carry by detectives and others. The PPK would later be featured in a number of Ian Fleming's James Bond novels (although secret agent Bond's PPK was chambered for the less powerful .32 ACP cartridge) and today is being produced in .380 caliber under license in the USA.

Derived from the Walther PP is the Russian Makarov service pistol, chambered for the 9x18mm Soviet cartridge (actually about a 9.2mm) that was derived from the .380. After the fall of the Iron Curtain, Makarov pistols were chambered for the .380 ACP and imported into the USA. The 9mm Mak and the .380 are not interchangeable, but the Russian cartridge is so similar that Makarov 9x18mm and 9x17mm pistols use the same magazine.

The .380 fills an important niche among cartridges for semi-automatic pistols and it is one of the best selling handgun cartridges in the world. Other popular and enduring .380 autoloaders include the Bersa 380, Colt Mustang PocketLite, SIG Sauer P238 and the streamlined SIG SAUER P232 series. Reviews of the aforementioned pistols can be found on the Product Reviews page.

The .380 actually uses 9mm (.355" diameter) bullets. Factory made .380 cartridges are generally loaded with jacketed bullets weighing 85-102 grains. The old 95 grain FMJ bullet is no great man stopper, but aggressive hollow point designs, such as the Federal Hydra-Shok, Winchester Silvertip and Remington Golden Saber give .380 pocket pistols stopping power percentages similar to snub-nosed .38 Special revolvers. .380 factory load ballistics are usually derived in 3.75" or 4.0" barrels, which reflects the cartridge's performance in full size pistols.

The .327 Magnum was introduced by Federal Cartridge in 2008. It is the latest in a long line of .32 caliber revolver cartridges with .337" diameter cases that use .312" diameter bullets. These include the .32 S&W, .32 S&W Long, .32 H&R Magnum and, finally, the .327 Federal Magnum. Any .327 Magnum revolver can shoot all of these cartridges. A .327 Magnum revolver can also shoot the .32 ACP auto pistol cartridge, which is a semi-rimmed design that uses the same .337" case diameter and .312" bullets as the .32 revolver cartridges.

The .327 Magnum cartridge looks like a somewhat smaller version of the .357 Magnum cartridge. This makes sense, as the .327 was designed to be chambered in revolvers with .38 Special length cylinders and the .357 Magnum was developed from the .38 Special.

.327 Federal Magnum factory loads from industry giant ATK's Sporting Division, which are sold under the Federal, Speer and American Eagle brands, are offered with 85, 100 and 115 grain jacketed bullets. Factory ballistics are measured in 4" vented barrels to simulate use in service revolvers.

The first revolver chambered for the .327 was the Ruger SP101, which is supplied with a 3" barrel. This is a strong, small frame revolver designed for concealed carry. It can safely handle the .327 Magnum's pressure, but was an unfortunate choice in other respects. The 3" barrel is insufficient to deliver the cartridge's full performance, the muzzle blast is obnoxious and the recoil in the little revolver is intimidating to all but the most experienced shooters. It is an unpleasant combination to shoot. If your choice for home or personal defense is a Ruger SP101, stick with .32 H&R Magnum ammunition.

Far more suitable platforms for the .327 Mag. are the medium frame Ruger GP100 (DA) and Ruger Blackhawk (SA) revolvers. These hand filling revolvers come with 4.25" and 5.5" barrels respectively and weigh 40-48 ounces. The .327 GP100 has a seven shot cylinder and the Blackhawk has an eight shot cylinder. Full reviews of the .327 Ruger SP101, Blackhawk and GP100 revolvers can be found on the Product Reviews page.

The Comparison

We will compare the .327 Federal Magnum and the .380 ACP in velocity, kinetic energy, trajectory, sectional density, bullet cross-sectional area and recoil. While the .327 Magnum has both personal defense and hunting applications, the .380 is used almost exclusively for personal protection, so we will compare these two cartridges in that role. ATK/Federal designed the .327 and offers factory loaded ammunition for both cartridges, so we will use Federal Premium loads with the Company's excellent Hydra-Shok bullets for comparison.

To represent the .327 Magnum, we will use the Federal Premium Personal Defense Low Recoil load, which is loaded with an 85 grain Hydra-Shok (H-S) JHP bullet. This load is 100 fps slower than full power .327 Magnum loads, but it is the premier self-defense load in the caliber. I would like to take this opportunity to thank the fine folks at Federal Cartridge for supplying us with .327 ammunition for our series of gun and ammo reviews.

The.380 ACP will be represented by the Federal Premium Personal Defense Low Recoil load using a 90 grain Hydra-Shok JHP bullet. Although it is designated "low recoil," this is actually Federal's highest velocity .380 offering. Federal provides accurate ballistic data for both calibers and we will use their figures in this comparison.


Velocity is important for initiating bullet expansion and it is the most important factor in calculating kinetic energy. Higher velocity flattens trajectory, making hitting easier at extended and unknown ranges. Here are the velocities in feet per second (fps) of our comparison loads at the muzzle, 50 yards and 100 yards.

  • .327 Mag, 85 gr. H-S: MV 1400 fps, 1220 fps at 50 yards, 1090 at 100 yards.
  • .380 ACP, 90 gr. H-S: MV 1000 fps, 910 fps at 50 yards, 850 fps at 100 yards.

As you can see, there is really no comparison in terms of velocity. The .327 is much faster at all ranges. In fact, the .327 is 90 fps faster at 100 yards than the .380 is at the muzzle. This bodes well for the .327 in terms of energy, trajectory and bullet expansion downrange.


Kinetic energy is defined as the ability to do work. In this case, the "work" involved is primarily powering bullet penetration and expansion. Both are, of course, necessary for lethality. Here are the energy figures in foot-pounds (ft. lbs.) for our comparison loads at the muzzle (ME), 50 yards and 100 yards.

  • .327 Mag, 85 gr. H-S: ME 370 ft. lbs., 280 ft. lbs. at 50 yards, 225 ft. lbs. at 100 yards.
  • .380 ACP, 90 gr. H-S: ME 200 ft. lbs., 165 ft. lbs. at 50 yards, 145 ft. lbs. at 100 yards.

Comparing these two personal protection loads, the .327 has a 170 ft. lb. energy advantage at the muzzle and 115 ft. lb. advantage at 50 yards. The .327 wins the energy comparison by a wide margin.


Sometimes the need for personal defense occurs at greater distances than anticipated. Seven yards or less may be typical, but sometimes bad guys do not play by the rules and bring slug shooting shotguns, rifles or magnum revolvers to gunfights. In such circumstances the need to reach out and touch someone makes a flat trajectory important. This particularly applies to those who carry a handgun for protection against two-legged predators when camping, fishing or hiking.

Federal Cartridge bases their handgun trajectory information on a 25 yard zero. Here are the Federal trajectory figures (in inches) for our selected cartridges, based on a 25 yard zero from a gun with iron sights.

  • .327 Mag, 85 gr. H-S: +/- 0" at 25 yards, -0.4" at 50 yards, -2.2" at 75 yards, -5.7" at 100 yards.
  • .380 ACP, 90 gr. H-S: +/- 0" at 25 yards, -1.5" at 50 yards, -5.6" at 75 yards, -12.5" at 100 yards.

Those trajectory figures clearly illustrate the advantage of the .327's high velocity. Even with a 25 yard zero (and the .327 could easily be zeroed at 50, 75 or 100 yards), its 5.7" drop at 100 yards allows a center of mass hold at that distance. With over a foot of drop at 100 yards, the .380 is simply outclassed by the flat shooting .327.

Sectional Density (SD)

Sectional Density is the ratio of a bullet's weight (in pounds) to its diameter squared (in inches). SD is important when comparing cartridges and loads because, other factors (such as impact velocity and bullet design) being equal, the bullet with the greatest SD will penetrate deeper, creating a longer wound cavity and increasing tissue destruction. Superior SD also improves the penetration of barrier materials, giving the bullet a better chance to reach a target on the other side (other factors being equal).

The actual bullet diameter for the .327 is .312". The actual bullet diameter for the .380 ACP is .355" Here are the SD's for our selected bullets.

  • .312", 85 grain = .125 SD
  • .355", 90 grain = .097 SD

Poor SD is one of the .380's weaknesses. As you can see, although is it 5 grains heavier, the .308's 90 grain bullet is clearly inferior to the .327's 85 grain bullet in sectional density. Both Hydra-Shok bullets typically expand well, but based on its SD, the .327 has the potential for deeper penetration.

Cross-Sectional Area

Other things (such as bullet construction and expansion ratio) being equal, a fatter bullet makes a larger hole and consequently a wider wound cavity with increased area. Here are the cross-sectional areas of our two calibers.

  • .312" = .0760 sq. in.
  • .355" = .1005 sq. in.

Obviously, the .380 (.355" diameter bullet) has an advantage over the .327 (.312" diameter bullet) in cross-sectional area.


Recoil is always bad. It makes accurate bullet placement more difficult by encouraging flinching and it increases the recovery time required between shots. For self defense handgun cartridges, you can definitely have too much power. In full size pistols, the .380 and .327 are both easily controllable. In pocket pistols, the .380's recoil becomes sharp and the .327's recoil is unpleasant. I would not recommend the .327 for use in pocket revolvers.

Here are some approximate recoil energy (ft. lbs.) and velocity (fps) figures for our comparison loads fired in typical full size (and weight) handguns.

  • .327 Mag, 85 gr. at 1400 fps; 3 lb. revolver: 2.2 ft. lbs.; 6.8 fps
  • .380 ACP, 90 gr. at 1000 fps; 1.5 lb. pistol: 2.5 ft. lbs.; 10.4 fps

Somewhat surprisingly, in full size pistols of typical weight, the .380 actually delivers more recoil than the .327. This is entirely due to the fact that semi-autos like the Walther PP and Makarov are about half the weight of a Ruger Blackhawk revolver. Recoil, if other factors are constant, is inversely proportional to gun weight.

Not measured here, but worth noting, is that the muzzle blast from a .327 Magnum is decidedly more pronounced than the blast from any .380 pistol I have ever fired. Indoors, a .327 would be very loud, indeed.

Summary and Conclusion

As you can see from the foregoing, the .327 Magnum exceeds the performance of the .380 ACP in every category, except bullet cross-sectional area. In a Ruger Blackhawk revolver, the .327 even offers an extra shot (eight instead of seven), compared to most .380 pistol magazines. Its flatter trajectory also makes the .327 far more versatile, suitable for the handgun hunter seeking small game or predators, as well as for personal protection against two-legged predators. Typical .327 revolvers, such as the Ruger GP100 and Blackhawk, come with adjustable sights and are usually much more accurate than .380 service pistols. The .327 can handle mild, lower pressure practice loads, such as the .32 Long and .32 H&R cartridges, while auto pistols are restricted to ammunition loaded within tight pressure limits to ensure reliable functioning.

The .380's main advantage is in the number and wide price range of new and used pistols on the market and the wide distribution of .380 ACP ammunition. Greater availability generally means lower ammunition prices. For concealed carry, no .327 revolver, including the Ruger SP101, is as light and compact as a .380 pocket pistol. The .380 ACP remains the optimum cartridge for deep concealment pistols. For these reasons, both calibers have their place in the scheme of things.

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Copyright 2012 by Chuck Hawks. All rights reserved.