Compared: The .327 Federal Magnum and 9mm Luger (9x19mm Parabellum)

By Chuck Hawks

The 9mm Luger, 9mm Parabellum or 9x19mm (all three nomenclatures are in common use) is one of our oldest autoloading pistol service cartridges, adopted by the German military in 1908. This well designed cartridge is one of the best and most popular handgun cartridges in the world. It is the NATO standard pistol cartridge and it is used by more of the world's armies than any other cartridge. The 9x19 is offered in more pistols than any other centerfire cartridge, from sub compacts to full size service pistols. Over the years, immensely popular pistols have been chambered for the 9x19mm cartridge. Notable examples of these include the Luger P-08, Browning P-35 High Power, Walther P-38, Beretta 92 and Glock 17. To call the 9x19 a commercial success is an understatement.

It is a powerful cartridge and requires a locked breech pistol, typically of the Browning tilt barrel, short recoil operated design. The SAAMI maximum average pressure is 35,000 psi and NATO spec ammunition is loaded hotter, so simple blow-back operation is not practical.

The 9mm uses .355" diameter bullets. 9x19mm cartridges are generally loaded with jacketed bullets weighing 90-147 grains, with 115 and 124 grains being the most common bullet weights. 9mm FMJ bullets are not great man stoppers (no FMJ bullet is, in any pistol caliber), but modern hollow point designs, such as the Federal Hydra-Shok, Hornady XTP, Winchester Silvertip and Remington Golden Saber give 9mm pistols serious stopping power. 9x19mm factory load ballistics are derived in 4" barrels, which reflects the cartridge's performance in full size and compact service pistols, such as the ubiquitous Glock 19.

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 was designed for use in revolvers with .38 Special length cylinders and it looks like a somewhat smaller version of the .357 Magnum cartridge. .327 Federal Magnum factory loads from the ATK Sporting Division, which are sold under the Federal, Speer and American Eagle brands, are offered with 85, 100 and 115 grain bullets. Factory ballistics are measured in 4" vented barrels to simulate use in revolvers. I'd like to thank our friends at ATK for supplying the ammunition used in our series of reviews and articles about the .327 Magnum.

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. It can safely handle the .327 Magnum's pressure, but the 3" barrel is insufficient to deliver the cartridge's full performance, the muzzle blast is excessive and the recoil is obnoxious. It is an unpleasant combination to shoot. If your choice for home or personal defense is a Ruger SP101, use.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 9x19mm in velocity, kinetic energy, trajectory, sectional density, bullet cross-sectional area and recoil. While the .327 Magnum has both personal defense and hunting application, the 9x19 is used almost exclusively for personal protection and in service pistols, so we will compare these two cartridges in that light. 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 (H-S) 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 JHP bullet. This load is 100 fps slower and 15 grains lighter than full power .327 Magnum loads, but it is the most common self-defense load in the caliber.

The 9x19mm will be represented by the Federal Premium Personal Defense load using a 124 grain Hydra-Shok JHP bullet. This load is not from Federal's Low Recoil line. Although Federal offers a Low Recoil 9x19mm load using a 135 grain Hydra-Shok bullet at 1060 fps, most readers will be more familiar with full power, 124 grain 9x19mm cartridges. Federal provides ballistic data for both calibers taken in 4" barrels, so 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 ranges and particularly at unknown ranges in the field. 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.
  • 9x19mm, 124 gr. H-S: MV 1120 fps, 1030 fps at 50 yards, 960 fps at 100 yards.

As you can see, the .327 is faster than the 9x19. It has a 280 fps advantage at the muzzle and a 130 fps advantage at 100 yards.


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.
  • 9x19mm, 124 gr. H-S: ME 345 ft. lbs., 290 ft. lbs. at 50 yards, 255 ft. lbs. at 100 yards.

Comparing these two personal protection loads, the .327 has a modest 25 ft. lb. energy advantage at the muzzle, while the 9x19 has a modest 30 ft. lb. advantage at 100 yards. At 50 yards it is almost a dead heat. Call the energy comparison a functional tie, the .327's velocity advantage being negated by the 9mm's heavier bullet.


Sometimes the need for personal defense occurs at greater distances than anticipated. Seven yards or less may be the statistical average, but sometimes bad guys do not play by the rules and bring slug shooting shotguns, rifles or magnum revolvers to outdoor 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 loads, based on a 25 yard zero using handguns 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.
  • 9x19mm, 124 gr. H-S: +/- 0" at 25 yards, -1.0" at 50 yards, -4.0" at 75 yards, -9.3" at 100 yards.

Those trajectory figures clearly illustrate the advantage of the .327's high velocity. Even with a 25 yard zero (and either cartridge shoots flat enough to be zeroed at 50 or 75 yards), the .327's 5.7" drop at 100 yards allows a center of mass hold at that distance.

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 9x19 is .355" Here are the SD's for some common bullet weights in both calibers.

  • .312", 85 grain = .125 SD
  • .312", 100 grain = .147 SD
  • .355", 115 grain = .130 SD
  • .355", 124 grain = .141 SD

As you can see, comparing the two most common bullet weights in each caliber, there is little to choose in terms of SD. With comparable bullet weights, penetration should be about the same.

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 a larger area of destruction. Here are the cross-sectional areas of our two calibers.

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

Clearly, the 9x19's .355" diameter bullet has an advantage over the .327's .312" diameter bullet in cross-sectional area.


Recoil is always bad. It makes accurate bullet placement more difficult by causing flinching and increases the recovery time required between shots. Self defense handgun cartridges can be too powerful. In full size pistols, the 9x19 and .327 are both controllable. In sub-compact guns, their recoil and muzzle blast become unpleasant.

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

  • .327 Mag, 85 gr. at 1400 fps; 3.0 lb. revolver: 2.2 ft. lbs.; 6.8 fps
  • 9x19mm, 124 gr. at 1120 fps; 2.0 lb. pistol: 4.4 ft. lbs.; 12 fps
  • 9x19mm, 124 gr. at 1120 fps; 3.0 lb. pistol: 3.0 ft. lbs.; 8.0 fps

In full size pistols of typical weight, the 9x19 delivers about twice the recoil of the .327 Magnum. This is due to the fact that typical service pistols for the 9x19 are about 2/3 the weight of a Ruger Blackhawk, our representative .327 Magnum revolver, and recoil is inversely proportional to gun weight. In guns of the same weight the 9x19 kicks a little more than the .327, but the difference between them is reduced.

Summary and Conclusion

As you can see from the foregoing, the .327 Magnum and 9x19mm cartridges are closely matched for self defense purposes. The 9x19 wins the cross-sectional area comparison and the .327 wins the velocity and recoil comparisons. In the other categories, the two are virtually even. Choosing between them may come down to the buyer's preference for a revolver or an autoloading pistol.

The .327's flat trajectory makes it suitable for the handgun hunter seeking small game or predators, an application for which the 9x19 is not generally considered. Typical .327 revolvers, such as the Ruger GP100 and Blackhawk, come with adjustable sights and are usually more accurate at extended ranges than 9x19mm auto pistols. The .327 can handle mild, lower pressure practice loads, such as the .32 Long, .32 H&R and reduced power .327 reloads, while 9x19mm semi-automatics are restricted to ammunition loaded within fairly tight pressure limits to ensure reliable functioning.

Single stack 9mm pistols generally offer a magazine capacity of about eight rounds, the same cartridge capacity as a Ruger Blackhawk revolver. However, double stack 9mm service pistols are very common and these typically offer 12 to 17 round magazines. The 9mm's biggest advantage is the number and wide price range of new and used pistols in the caliber and the world-wide distribution of 9x19mm ammunition. Greater ammo availability generally means lower prices and you will often see 9mm ammo on sale at a reduced price. For concealed carry, no .327 revolver, including the Ruger SP101, is as light as a sub compact 9x19 pistol like the Kahr PM9.

For all of these reasons, both the .327 Federal Magnum and the 9mm Luger are useful calibers. Rather than having to choose between them, I prefer to own handguns in both calibers.

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Copyright 2012 by Chuck Hawks. All rights reserved.