The 9mm
The 9mm cartridge is adaptable to many bullet types and weights. Left to right: Civil Defense 50-gr. HP, Speer 115-gr. FMJ, Aguila 124-gr. FMJ, Hornady 135-gr. FTX, and Hornady 147-gr. XTP. author photo

We all know it simply as the 9mm, but it goes by a variety of names: 9mm Luger, 9mm Parabellum, 9x19mm, 9mmP, and I’m sure there are others depending on which patch of dirt you’re standing on is located in this world.

To really know the 9mm, you need to know a bit of Latin, understand the profound impact a German-designed pistol had on arms and cartridge development, and the 9mm’s ability to reinvent itself—especially at times in the recent past when it was nearly written off as inadequate.

The 9mm
The 9mm cartridge is ubiquitous. This is just a tiny sample of 9mm ammo manufactured in the US and abroad. author photo

“If You Want Peace, Prepare for War”

This year the cartridge will have been around for 115 years, and that makes it older than the .45 ACP, which debuted in 1904; and closer in age to the .38 Special, which was introduced in 1889. There are numerous reasons why this cartridge is as popular as ever, but the top line is this: the 9mm has plenty of power, offers decent accuracy, has minimal recoil, is inexpensive, and can be adapted to a variety of platforms: full-size to subcompact pistols, revolvers, and carbines.

The 9mm
Top: A German soldier with a P08 Luger. Bottom: An example of a post-WWI DWM Model 1914 Navy Luger with a 6-inch barrel and two-position Navy rear sight. courtesy Rock Island Auction

In the beginning, the 9mm was not a cartridge in search of pistol, but a pistol—the Luger—in search of a new cartridge. In 1900, Austrian firearm designer Georg Luger basically reworked the design of the Hugo Borchardt C-93 pistol. He made the Luger pistol smaller and more reliable (relatively speaking) and chambered it in the 7.65x21mm (which is also known as 7.65 Parabellum and .30 Luger to us cartridgephiles). The Luger pistol used a toggle system, which was as odd to revolvers shooters of that time as polymer-frame pistols were odd to shooters 30 years ago.

The Swiss Army bought a crateful of the new Lugers in 7.65mm…not the payday that manufacturer Deutsche Waffen-und Munitionsfabriken (DWM) had in mind, but a start. The Germany military offered the contract Georg Luger and his employer DWM most wanted. That deal would mean not only crates, but containers and railroad cars filled with pistols and ammunition for those pistols. However, the Germans wanted a bigger, more powerful cartridge, so DWM and Georg Luger took the 7.65mm Parabellum cartridge case, shortened it, and blew out the bottleneck to accept a larger diameter bullet and more powder. They named it the 9x19mm Parabellum, and in 1902, a new cartridge was born.

The 9mm
An example of a post-WWI DWM Model 1914 Navy Luger with a 6-inch barrel and two-position Navy rear sight. courtesy Rock Island Auction

The DWM company motto was Si vis pacem, para bellum, which is Latin for “If you want peace, prepare for war.” (Told you there would be a Latin lesson.)

How It Compares

From a technical point of view the 9mm is a tapered, rimless cartridge that holds a 9mm (.380 in.) diameter bullet. The case has a length of 19mm (.754 in.) and a rim diameter of 9.96mm (.392 in.). Maximum overall length is 29.69mm (1.169 in.) and it headspaces on the case mouth. As specified by SAAMI maximum pressure is 35,001 psi.

The 9mm started life with a 124-grain FMJ bullet. Original 124-grain FMJ bullets achieved a muzzle velocity of about 1200 fps, generating 384 ft.-lbs. of muzzle energy. It was a hot load then, and it is now. Part of the reason it was loaded so hotly was to reliably operate the Luger pistol’s toggle action.

The 9mm
The MP40 was a German submachine gun chambered for 9mm. web photo

Compare this to the .38 Special load with a 158-grain bullet, which has a muzzle velocity of 940 fps (260 fps less than the 9mm) and 310 ft-lb. of muzzle energy (74 ft.-lbs. less). The U.S. military .45 ACP load with a 230-grain FMJ has a muzzle velocity of 830 fps (370 fps less than the 9mm) and muzzle energy of 352 ft.-lbs. (32 ft.-lbs. less).

The law enforcement market in the U.S. used the .38 Special nearly exclusively for decades, and the U.S. military used the .45 ACP from 1911 through the Vietnam War, about 85 years. But on paper, the 9mm has a distinct edge over both cartridges. It generates less recoil than the .45 ACP, and since the 9mm has a smaller diameter, it had a capacity advantage as well: 8+1, compared to the 7+1 of the .45 ACP. It wasn’t long before 9mm pistols would nearly double that magazine capacity. The ability to sustain fire without reloading is plus in a gunfight, and more military forces and LE departments started to make the comparison: the .38 Special with less power and maximum six-round capacity in a revolver, versus a 9mm semi-automatic with more power and a nine-round capacity.

The 9mm
The Smith & Wesson Model 39 was the first U.S. manufactured semiautomatic pistol and ushered in the acceptance of the 9mm round with U.S. shooters. An early aluminum alloy frame Model 39 with long extractor is at top; note the shorter extractor on the Model 39-2 at bottom. courtesy Smith and Wesson

But the 9mm has not been immune to other calibers trying to take its place. The .40 S&W unseated the 9mm in the mid to late 20th century in many applications, but the 9mm has staying power. Just when some would discount it, new propellants and bullet design literally propelled the round ahead and away from the maddening crowd of other calibers.

How the 9mm Proved Itself

The 9mm really gained traction in 1904 when the German Navy ordered pistols. The Navy was typically quicker to adopt new technology, and the Luger pistol chambered in 9mm was cutting-edge weaponry at the time. In 1908 the Germany Army adopted the pistol and issued it to troops as the P08. Mauser and Steyr, manufacturers that were competing with the Luger pistol and the 9mm cartridge, joined the pack and retooled their pistols (the C96 and M1912, respectively) in 9mm. Other would follow suit.

The 9mm
The SIG-Sauer P210 is considered one of the most accurate factory-made 9mm pistols. This example is a late model manufactured in 2015. The P210 was adopted by the Swiss military in 1949. courtesy of SIG USA

It was in the trenches of World War I that the 9mm cut its teeth. Fast to shoot and reload, light recoil, accurate, and with that 8+1 round capacity, the Luger in 9mm had advantages against British and French revolvers. Then, later in the war, a new weapon was being developed and the 9mm was tapped to fuel it. The Bergmann MP 18 was the first successful submachine gun and was deployed late during the Great War. The 9mm moved up in status, since now it was not only a cartridge for handguns but also for a lightweight, fully automatic carbine.

By the end of WWI, even though the 9mm had gained a foothold with military forces, the Luger pistol was dated. The new-fangled semi-automatic conceded to more modern designs that were less expensive to manufacture and used more reliable operating systems.

The 9mm
The Browning Hi-Power Standard was the first 9mm handgun with a large capacity magazine. This is a current model with adjustable sights and ambidextrous safety. Courtesy of Browning USA

But the 9mm was here to stay. Even John Browning wanted in on the 9mm, and adapted his short-recoil mechanism from the M1911 to his new Browning Hi-Power semi-automatic. It would be the last pistol design John Browning worked on, and would be introduced in 1935 by Belgium’s Fabrique Nationale several years after his death. The Hi-Power would eventually usher in a new genus of high-capacity 9mm semi-automatic pistols dubbed Wonder Nines in 1980s…but not before the 9mm was deployed in another world war.

The 9mm in World War II

The Blitzkrieg was set in motion by 1939, and countries around the globe were poised for a second world war. Many armies took with them handguns chambered in 9mm:

  • Germany adopted the Walther P38, an inexpensive, reliable pistol that was just as cutting edge as the Luger had been 40 years previous.

  • Poland used a Radom-manufactured FB Vis—basically a Browning design knockoff—chambered in 9mm.

The 9mm
The CZ 75 is a very popular double-action 9mm pistol overseas. It offers a high capacity magazine, DA/SA trigger system, and full metal receiver. Courtesy CZ USA
  • Canada took to arms with the Browning Hi-Power, and as ironic and incomprehensible as it seems, a small number of German units also carried the Hi-Power after capturing the factory in Belgium.

  • The Swiss had the SIG P210, perhaps the most accurate of all 9mm handguns then and since.

Submachine guns peaked during WWII. Britain issued the Sten, Germany the MP40, Italy had the Beretta Model 38, and Finland issued the Suomi M31—all chambered for the 9mm.

Italy, Britain, Japan, Soviet Union and others still used indigenous calibers for their pistols, but after WWII there was a major trend for all modern standing armies to convert to the 9mm. The U.S. resisted until 1985. (More on that later.)

The 9mm
The polymer frame Glock G17 was a game changer for 9mm handguns. This is a Gen 1 G17. mfg photo

Post-War Explosion

After WWII, pistol designs in 9mm grew out of nearly every country not under Soviet influence. (The Soviets had their own 9mm, which is the 9x18mm Makarov using a shorter case but same bullet diameter, but that’s a different story.) In the mid to late 20th century, SIG, FN Herstal, Steyr, Beretta, Smith & Wesson, Ruger and nearly every other small-arms manufacturer produced a 9mm pistol. And don’t forget Glock—in 1982 they debuted their first pistol, the G17, chambered for 9mm. Submachine guns evolved, too. The Israeli UZI and Heckler & Koch MP5 are just two of the more iconic submachine guns of recent history. Even the AR15/M16 was adapted to fire the 9mm.

Here in the U.S., the 9mm did not catch on as fast, partly due to the fact that no U.S. firearm manufacturers were building guns in the caliber. The U.S. Army kicked around the idea of changing to the 9mm in 1954, which led to Smith & Wesson designing the Model 39, a 9mm semiautomatic. After the Army abandoned the search, S&W took the pistol commercial and courted the law-enforcement market…and the U.S. ice cracked.

The 9mm
Colt adapted the M16/M4 AR platform to run the 9mm and created a compact submachine gun that operates similar to an M4. Courtesy Colt

In 1967, the Illinois State Police adopted the Model 39 pistol and the 9mm cartridge. It wasn’t long before other U.S. manufacturers were chambering pistols in 9mm. In the 1980s, law-enforcement agencies started to notice 9mm pistols and traded their six-shot revolvers for pistols like the Beretta 92, SIG P226, Glocks and others. Suddenly, law enforcement almost everywhere was geared up with 9mm pistols.

The Infamous Miami Shootout

The most common 9mm load for law enforcement prior to the development of the Federal Hydra-Shok load was a 115-grain+p+ using a jacketed hollow-point bullet. Sometimes referred to as the “Illinois State Police” load, this cartridge is still available and offers a muzzle velocity of 1300 fps and 432 ft.-lbs. At last check, 60 percent of U.S. law enforcement agencies, including the FBI, use the round. In fact, the FBI switched back to the 9mm cartridge in 2015, which is ironic since agents armed with 9mms were outgunned in the 1986 FBI Miami Shootout.

The 9mm
The Heckler & Lock P7 helped usher in the era of “Wonder Nines.” This 9mm is unique because it uses a squeeze cocker mechanism to fire the pistol. Courtesy HK USA

The shootout involved eight FBI agents and two bank robbers. In the aftermath two agents were killed, five were wounded. The suspects were also killed in the gunfight and the ensuing investigation found the 9mm pistols that agents used in the fight lacked power. The suspects were hit numerous times with 9mm rounds. The FBI changed gears and adopted the more powerful 10mm Auto cartridge, but that proved too powerful and difficult for the average agent to control, so the 10mm was downsized to the .40 S&W. That round nearly drove the 9mm out of aw enforcement agencies.

Current Military Use

Most current militaries issue a 9mm sidearm. To the angst of some in the U.S. military, the .45 ACP was deep-sixed in favor of the 9mm in 1985, when the 1911 was replaced by the Beretta M9 as the official sidearm.

The 9mm
Revolvers have also been chambered in 9mm. This Ruger LCR9 (top) is a current example. Most revolvers chambered for 9mm must use a moon clip (bottom) to hold the rimless cartridges. mfg photos

The NATO 9mm standard rounds are loaded to M882 specifications, meaning a 124-grain full-metal jacket bullet is loaded to a muzzle velocity of about 1260 fps. What many users of the round have found is that the 9mm underperforms compared to the former .45 ACP. In fact, the joke among military personnel is there’s a reason that 9mm handguns have twice the magazine capacity—you need to shoot the enemy at least twice to put them down. The U.S. military has indicated that they are considering hollow-point ammo in the Modular Handgun System, but this is not final. That’s important, because rounds such as the Speer Gold Dot Hollow Point put the 9mm in a different class compared to older 9mm loads.


These five loads were designed to save your life. Here’s how they fared, in the gun and downrange where it counts.

Defensive Handgun Ammo Test

However, the bottom line is that the 9mm offers more rounds carried on person, less felt recoil, and speed on target with a second shot. Add to this the fact that 9mm rounds are less expensive than .40 S&W, .45 ACP and other cartridges. The advanced technology in projectiles being manufactured offers stopping power with 12 to 18 inch penetration. Effective, to say the least, and tests performed by the FBI’s ballistics lab again prove the 9mm is more effective on paper. In fact in 2015 the FBI adopted a new 9mm round, the Speer 147-grain Gold Dot G2. This is the next generation of 9mm ammo that uses a bullet with a shallow dish filled with a high-performance elastomer. On impact, the elastomer starts the expansion process, resulting in uniform expansion and more consistent penetration across barrier types, gun platforms and barrel lengths. The Gold Dot G2 has a 970 fps muzzle velocity and 307 ft-lb of energy.

The 9mm
Smith & Wesson has produced a number of high capacity 9mm handguns since the original Model 39. This is a Model 5906. Courtesy S&W

Will the 9mm survive another 100 years? More than likely, yes. It is a round that has a sweet spot of moderate recoil, accuracy and power and is available in pistols ranging from sub-compacts to full size. Make mine a 9.

Robert A. Sadowski is the author of 50 Guns That Changed the World, Gun Trader’s Guide, Shooter’s Bible Guide to Combat Handguns, and numerous other gun books. See all of his titles here.

The 9mm
The Beretta 92FS (bottom) was adopted by the U.S. military in 1985 as the M9. The M9A3 (top) was introduced by Beretta as a replacement for the M9 in 2015. mfg photo