I never thought I would have to explain this particular thing, but here we are. You’re probably already aware that 9mm is the most popular round on the planet. Why would I have to explain something so simple and popular? Because it’s not that simple. Heck, even I learned something digging into this one.
There are so many different designations for 9mm, and so many version of 9mm that aren’t the same. You will commonly see ammo boxes labeled 9x19mm, 9mm Luger, 9mm Parabellum, or 9mm NATO. Most people think they’re the same thing. But why so many different designations?
Well, first, because there are many different countries making ammo. Second, because there is more than one standard that those companies have to follow. One is SAAMI and the other is CIP. SAAMI is the Sporting Arms and Ammunition Manufacturers Institute. CIP is the Commission internationale permanente pour l’épreuve des armes à feu portatives.
To dumb it down, SAAMI is the U.S. institute that ensures that all ammunition is made to the same standards. CIP is the European version of SAAMI.
That alone gives us 9mm Luger, 9mm Parabellum and 9x19mm. This is your “standard” 9mm that is used is most pistols. They are all the same round, loaded to the same specs, regardless of which institutional standard they are following.
Then there’s 9mm NATO, which is a tad different. These are essentially military rounds and are loaded to higher pressures, akin to 9mm Parabellum +P. It has a bit of extra powder in the cartridge and produces pressures slightly higher than SAAMI allows. If you’re handgun isn’t rated for a steady diet of +P rounds, stay away from NATO rounds.
That’s the simple part. Then we have all the “other” 9mm cartridges: 9x18mm, 9x17mm, 9mm Corto, 9mm Kurtz, 9mm Browning, 9x23SR, 9x23 Winchester, 9x21mm. Here’s where things get fun.
The 9x18mm cartridge (or 9x18mm Makarov, as it’s usually labeled) is different than regular 9x19mm. This round was designed for the 9mm Makarov pistol. The case is slightly shorter than the 9x19mm.
The 9x17mm, 9mm Browning, 9mm Short, 9mm Corto, and 9mm Kurtz cartridges are all .380 ACP. They’re very similar to 9x19mm, but the difference in dimensions and powder charge mean they are not interchangeable.
You can shoot .380 ACP in a pistol chambered for 9x19mm but it probably won’t have enough energy to cycle properly. You shouldn’t be able to fit a 9x19mm round into a .380. If you could, you’d be making a hand grenade you’re not fast enough to throw.
The 9x23SR round is also known as the .38 ACP. You’ve probably never heard of either. I hadn’t until I started looking up the various 9mm cartridges. This is different than the .380 ACP and .38 Special. The case is semi-rimmed, hence the SR. This is a round you’ll probably never see at your local range or gun store.
The 9x23mm is actually a newer round developed by Winchester in 1996. The case is more than an eighth-inch longer than 9x19mm, so it’s obviously not compatible. Even though it’s new, this is another one that you’ll probably never see. It fell flat on its face at launch and hasn’t gotten back up.
The 9x21mm is an Israeli round created by IMI (Israel Military Industries). This thing is so different in dimensions that it’s not compatible either. And it’s another one that is hard to find (outside of Israel, at least). It is also called 9mm IMI.
So when you’re buying ammo, stay with boxes labeled 9x19mm, 9mm Luger, 9mm Parabellum or just good ol’ 9mm. They are all the same round and will work just fine in your pistol.
Capt. Cayle Wills is a USCCA-certified firearms instructor and gunsmith at Higher Power Outfitters (1826 Tamiami Trail, Punta Gorda). Contact him at 941-916-4538 or Cayle@HigherPowerOutfitters.com.