Even if you know very little about guns, perhaps just what you’ve picked up from watching TV and movies, you’ve probably gathered there’s a round called 9mm.
As you learn more, you probably discover it’s a pistol round, but you’ll soon hear other terms like Luger and Parabellum. So you might wonder… what is the difference between 9mm, 9mm Luger, and 9×19 Parabellum?
In short, nothing.
9mm Luger and 9x19mm Parabellum refer to the exact same round. When someone refers to 9mm, they almost always mean 9x19mm.
However, there are also terms catering to specific variations of 9x19mm and other 9mm caliber rounds altogether.
Let’s clear up these terms so you know exactly what people are talking about when discussing 9mm.
First, we’ll check out why there are so many names, then get into a few common variations of 9x19mm.
Table of Contents
Where Does 9mm Luger Come From?
Let’s start by finding out where the 9mm Luger name began. To do that, we need to look at the round’s history.
Designed in 1901 by Austrian designer Georg Luger (whoop, there it is!), 9mm Luger was introduced the following year by German manufacturer Deutsche Waffen- und Munitionsfabriken (German Weapons and Munitions).
That 9mm paired with DWM’s Luger semi-automatic pistol, thus earning its name, 9mm Luger, from the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI).
Similarly, the round is designated 9 mm Luger by the Commission Internationale Permanente pour l’Epreuve des Armes à Feu Portatives (CIP)–note the addition of the space between 9 and mm.
Ok, But What About 9x19mm Parabellum?
While 9mm Luger got its name from external groups, 9x19mm Parabellum is the original official designation from DWM.
To understand where DWM got that name, you once again have to look at the origins of the round.
9x19mm Parabellum is derived from DWM’s earlier 7.65x21mm Parabellum cartridge and inherited the “Parabellum” tag. Not to mention, that Luger pistol we talked about earlier is known as the Pistole Parabellum or Parabellum-Pistole.
That still doesn’t answer the question of the word parabellum’s roots. Where did it all begin? The word comes from DWM’s motto, Si vis pacem, para bellum. This is Latin for “if you seek peace, prepare for war.”
(Looking for 9mm? Check out the best 9mm rounds for plinking and defense!)
Talk to Me About 9x19mm Variants
Now that you understand 9mm Parabellum/9mm Luger a little better, let’s look at some other variations on the cartridge.
The +P label indicates the round is a high-pressure load, though still not as high pressure as a magnum round might be. +P is achieved by simply packing more gun powder into a cartridge.
9mm +P ammo has 10% more pressure than a standard 9x19mm round. Per SAAMI specifications, the standard pressure for 9x19mm is 35,000 psi, while 9mm +P measures 38,500 psi.
The increased pressure boosts the round’s energy and velocity, creating better stopping power and ballistic performance. This makes +P ammo well-suited for self-defense.
However, not all guns are equipped to handle the pressure of +P ammo, so check that your pistol is compatible before use.
Prices accurate at time of writing
Prices accurate at time of writing
Rounds with even higher pressure than the typical +P round are marked +P+. It’s worth noting that SAAMI doesn’t list a standard pressure for +P+.
9mm NATO is 9x19mm ammo that conforms to NATO standards. Like 9mm +P, 9mm NATO is overpressurized, but not to the same extent. 9mm NATO has a service pressure of 36,500 psi.
By NATO standards, 9mm NATO has a bullet weight between 108-grains and 128-grains. NATO standards don’t state what type of bullet 9mm NATO rounds should use.
However, the Hague Convention bans expanding bullets in warfare; so, NATO rounds have full metal jacket ball bullets.
Other 9mm Rounds
All of that said, 9mm Parabellum/9mm Luger isn’t the only 9mm caliber round out there.
A few other rounds exist with 9mm classifications. Unlike the rounds we just discussed, these are entirely separate cartridges, but happen to have 9mm bullet diameters.
Let’s start with the 9x18mm Makarov, often called 9x18mm PM and officially designated 9mm Makarov by the CIP.
The 9x18mm Makarov was the standard pistol cartridge of the Soviet Union and Eastern Bloc in the second half of the 20th century. It could reasonably be called the Soviet’s counterpart to 9x19mm.
However, 9x18mm Makarov is no longer widely used. Given its ballistics, it never gained as much traction as the 9x19mm in the West.
On the other hand, 9x18mm Ultra did see popularity in the West, but only as a trend.
Developed in Germany in 1936, it didn’t get much attention until the early 1970s when Walther released the PP Super in 9x18mm Ultra for the West German Police. The round was released to the public in 1975.
Other guns chambered in 9x18mm Ultra followed, such as the Sig Sauer P230. The Walther PP Super was discontinued in 1979, and with that, the round’s popularity faded. You can still find the ammo today without too much trouble, especially if you shop online.
9mm Browning enters the field with better recognition than either of the last two rounds, but you probably don’t realize it. Known as .380 ACP in the United States, the official CIP designation is actually 9 mm Browning Court.
Its proportions are 9x17mm, making it the shortest of the 9mm rounds we’ve discussed here.
Arriving on the scene 1908, the round reached its peak during World War II when several European militaries used it. .380 ACP is perhaps most famously associated with the Walther PPK.
Some countries ban civilians from using military service cartridges, including 9x19mm. 9x21mm, or 9mm IMI, was developed for places like that.
The 9x21mm was created by Jager, an ammo manufacturer based in Italy. (Italy happens to be one of those countries banning 9x19mm for civilians, FYI.) It was later adopted by Israel Military Industries (IMI) for larger-scale production for multiple countries.
The U.S. never really caught the 9x21mm fever, but it saw popularity in other parts of the world, particularly in Italy. Despite lacking a dedicated following in the U.S., the round is commonly spotted in practical shooting competitions. This is due to the rimless casing, which makes it less likely to malfunction.
9x23mm Winchester is a relative newcomer, introduced in 1996. It was primarily intended to appeal to competition shooters, especially for practical shooting and defensive pistol shooting competition. A couple of advantages over other rounds at the time, pushed it into the competition arena.
First, more rounds could fit into a magazine, so fewer changes were required. Second, it delivered higher pressure. When used with a compensator, the gun had less muzzle flip from recoil.
Due to a combination of production delays, changes in competition standards, and robust competition, 9x23mm Winchester never really took off.
Even More 9mm
The rounds we’ve discussed are only a few of the many cartridges using 9mm. There are more pistol rounds in this caliber and even a revolver round (9mm Japanese revolver). You can even find a couple of rifle rounds (9×57mm Mauser and 9×39mm).
Unfortunately, many of these are no longer in production, making them rare, especially in the U.S.
So, what is the difference between 9mm, 9mm Luger, and 9×19 Parabellum?
As we’ve learned…nothing.
Despite the various naming schemes, 9mm most commonly refers to 9mm Luger or 9×19 Parabellum, which are, in fact, one and the same.
Still confused about ammunition and calibers? Check out our Bullet Guide for general ammo info and our Handgun Caliber Guide for handgun specific issues. You can also hit us with questions in the comments below! And if you’re in the market for 9mm ammo, be sure to check out The Best 9mm Ammo.