9mm Ammo: A Brief Overview


The most popular handgun cartridge of all time – the 9mm has been around for well over a century. Known as 9×19 Parabellum, 9mm Para or 9mm Luger, we often see these names used by

PMC 9mm 115 Full Metal Jacket rounds lined up

 different manufacturers to describe the cartridge. Created by Georg Luger in 1903, it carried the moniker of “9mm Parabellum” due to the original munitions plant in Germany where it was produced, pre-World War I.

The 9mm Parabellum cartridge is a rimless, tapered case that fires a 0.355” diameter bullet (9.01mm) and has a 19.15mm case length. Since its inception, it has steadily gained popularity with the military, law enforcement, and civilian customers worldwide. Most notably, here in the US, the 1980s and 90’s brought about a second resurgence in popularity due to both developing handgun technology and bullet design. At True Shot, it’s a cartridge that most of our customers purchase frequently and in bulk. We’ll go over some of the reasons behind its popularity and the bullet design that make it a favorite for many people.

Are 9mm Parabellum and 9mm Luger the same?

In short – yes, they are.  The Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) and the Commission Internationale Permanente, (CIP) are the American and European governing bodies that regulate ammunition. Basically, this naming difference comes down to CIP listing 9mm as 9x19mm Parabellum as the name for Georg Luger’s cartridge whereas SAAMI will not list a cartridge that is a registered trademark to avoid legal action from infringement lawsuits. Therefore, SAAMI lists 9mm as Luger to avoid a trademark issue with the previously registered 9x19mm Parabellum.

What does Grain Weight mean in Ammo?

If you’re new to shooting, you may wonder why some boxes of 9mm say 115 grain, while some show 124 grain and others 147 grain. This can get confusing since gun power is measured in grains but in this case, 115 grain, 124 grain, etc. refer to the weight of the projectile and has nothing to do with a powder charge.

What is the difference between 115 Grain v 124 Grain 9mm Ammunition?

Recoil difference between 115 grain 9mm v. 124 grain 9mm through a Smith & Wesson 2.0 5" Long slide
Recoil difference between 115 grain 9mm v. 124 grain 9mm through a Smith & Wesson 2.0 5″ Long slide. While the difference is slight, competitive and advanced shooters can tell a difference in recoil.

While the difference appears minor, with only a 9 grain weight difference between a 124 grain projectile and a 115 grain projectile, experienced shooters and competitive shooters will often prefer the 124 grain because there is less felt recoil and they can get follow-up shots on target quicker. Which begs the question, then why wouldn’t everyone shoot 124 grain over 115 grain? The answer is simple; 115 grain full metal jacket ammunition is typically cheaper than 124 grain and your average shooter usually can’t tell a difference. Note – You will find grain often abbreviated with gr, so 115 Grain and 115 gr are the exact same. The same thing goes with 124 grain – you will often see it as 124 gr and so on.

What is the difference between Full Metal Jacket and Hollow Point?


9mm Hollow Point (HP) v Full Metal Jacket (FMJ)
9mm Hollow Point (HP on the left) v Full Metal Jacket (FMJ on the right)

Full Metal Jacket or FMJ 9mm is the variant that most people will find on store shelves or online. The most popular bullet weights come primarily in 115 grains, 124, grains and 147 grains. As noted in a prior article, there may also be other names for the same type of ball ammunition that is commonly used for target or training purposes. Note – Total Metal Jacket or TMC is basically the same as FMJ projectiles, read our blog post on the difference here.

Hollow-Point or HP (you will also see these listed as jacketed hollow point or JHP, and other similar derivatives) is the second most common and is sometimes highly sought after for defensive use. Bullet technology has since evolved quite a bit since the cartridge was invented, and modern HP rounds make it a formidable defensive round.

What is Subsonic 9mm Ammunition?

PPU Subsonic 9mm 158 Grain Full Metal Jacket Box of 50 Rounds
Box of PPU 9mm Subsonic FMJ 158 Grain

Subsonic 9mm Ammo: Subsonic ammo is essentially geared towards use with a suppressor. It can commonly be found in grain weights ranging from 147 to 158 grains, and in both FMJ and HP. The heavier bullet (as compared to 115 grain or 124 grain) produces slower muzzle velocity thus making the round quieter, especially with the use of a suppressor (or silencer – these terms can be used interchangeably). It’s not as common as standard 9mm loads due to its intended use. It may not function well in a firearm without a suppressor because it is typically loaded with less powder – meaning it has a lower pressure and velocity (it’s moving slower).

Is buying bulk 9mm ammo better than buying by the box?

If you purchase 9mm ammo in bulk for target shooting, you will usually save money versus buying per box, as most retailers, us included, provide bulk ammo pricing discounts. So similarly to Costco, the larger the quantity you purchase, typically the less per round you will pay.

norma 9mm 115 grain fmj ammo can
Buying Ammo by the 1,000 round case, whether bulk or packaged is often cheaper than buying by the 50 round box.


What’s the deal with “+P” that I see on some boxes of ammo?

Have you ever wondered why some boxes of 9mm have “9mm +P” and others do not? The “+P” designation means it is a higher-pressure load. +P 9mm rounds are loaded with more gunpowder to increase the pressure and speed of the bullet (otherwise known as feet-per-second or FPS).

In order for 9mm rounds to be 9mm +P specification, SAAMI requires PSI greater than 35,000 psi and less than 38,500 psi (10% higher).

There are some specific uses for +P ammo, almost all of which are centered around self-defense. Some ammo manufacturers will have specific product lines of +P ammo that are geared towards the civilian or law-enforcement customer. What needs to be understood is that while +P ammo generally improves the performance of a cartridge, not all firearms are rated to handle +P ammunition. We recommend that you consult your owner’s manual or contact the manufacturer.

What does 9mm NATO mean? 

SAR USA 9mm 124 NATO spec 50 round box
SAR USA 9mm 124 Grain FMJ NATO spec

9mm NATO is a military designation for a specific 9x19mm loading. It is one of several officially adopted cartridges of NATO countries. This load variant differs from typical off-the-shelf target loads in that it operates at a higher pressure (similar to +P), and is found mostly in a 124 grain, FMJ configuration. Additionally, the case is sealed at the primer and around the neck with a colored lacquer-based sealant. It was created as a standardized, non-expanding, general-purpose issue cartridge that is compatible with a wide range of service pistols and sub-machineguns. If you see a box of this ammo, just be aware of its higher operating pressure if your firearm is not rated for such use.

So, which one do I need for my handgun?

  Without going down the rabbit hole of ballistics and terminal performance, we basically need to understand that FMJ should ideally be used for training and that HP should ideally be used for defensive purposes. You may see some HP ammo listed or advertised as +P as well, and assuming your handgun is rated to handle the load, these rounds are also preferable for self-defense.

Every cartridge and bullet design does have an intended purpose, always do your research into what you want and why. There is a wealth of information out there that goes very deep into ballistics and terminal performance. Some of which we’ll cover in a later article to help you really narrow down a purchase choice.

A note on exotic or boutique ammunition:

From time to time, we see 9mm loads with “special” attributes that are advertised. Some may prominently display certain capabilities like “ultra-high velocity” or “hyper-expanding bullet”. Unless there is actual data gathered from real-world use, it’s best to approach these rounds with caution and regard them as target ammo. There is likely no scientific data or case-use evidence that clearly shows they work as intended. Please be careful when considering this type of ammo.

So why is 9mm so popular?

The cartridge has a significant number of favorable characteristics for shooters of all skill levels. Aside from its wide availability, there is a rather enormous number of firearms chambered in this cartridge. Most are handguns, like “full-size” service pistols used by law enforcement or the military, or “compact” variants that may be conceal carried by the average person. They have standard magazine capacities ranging from 12 to 19 rounds depending on the model. By comparison to larger cartridges like .40S&W and .45 Auto., this is a significant increase in capacity with very little, if any, decrease in performance when specifically discussing these three common handgun rounds.

Other key benefits compared to .40 S&W and .45 Auto include:

Reduced size and weight – in some cases where a concealable firearm is needed, you’re still able to maintain a good magazine capacity. You can have two of the same make and model handguns chambered in different cartridges and the one chambered in 9mm will always have greater magazine capacity.

Speaking of magazine capacity, more is typically better. No one has ever complained about having too much ammo when it comes to self-defense or fighting bad guys. There is no telling how many rounds you need when your life is on the line.

More manageable recoil can be had with 9mm in comparison to .40S&W and .45 Auto. This is important because it allows us to quickly and more consistently hit what we are aiming at. You can begin to see why this would matter in a self-defense situation.

Price per round – this is a factor that’s harder to ignore. 9mm is generally less expensive compared to its larger counterparts. It can really add up over time. We want to be proficient with our firearms and that means training – we can’t train if we can’t afford to do so.

There are a fair number of affordable handguns chambered in 9mm. This goes hand-in-hand with more affordable ammunition. There are now more options than ever, further proliferating the 9mm cartridge into common use in the U.S. Even law enforcement and government agencies have budgets, which is partly why so many choose 9mm service pistols.

Wrapping it up:

Even with all of this information, there is still much more on 9mm in terms of its history, performance, firearm design, and use worldwide. In future posts, we can dive deeper into the subject with more detailed information per subject or category. We want to provide you with a base amount of information to help you continue to build your knowledge about the firearm world.

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