Last time, we started off by talking about the nuts and bolts of handgun ammunition. Today we’re picking up that discussion where we left off.
Handgun ammo is generally made for use in pistols or revolvers. Yes, a revolver is technically a pistol, but I’m talking about semi-automatic pistols. There is a difference between the two. In a revolver round, the base or rim of the cartridge is larger in diameter than the case. If it wasn’t, the rounds would simply fall through the revolver’s cylinder.
Some common revolver calibers are .38 Special, .357 Magnum and .44 Magnum. In many revolver calibers, it’s the diameter of the rim, not the diameter of the bullet, that is used in the name. Thus, a .44 Magnum fires a bullet that is actually .429 inches in diameter. You will also find revolvers chambered in rimfire calibers, as their rims are a larger diameter.
Some revolvers can fire multiple calibers. If you have a .357 Magnum revolver, it can shoot .38 Special ammo. Despite very different names, the only difference between these two rounds is the length of the cartridge and how much powder that cartridge can hold. The .38 Special is shorter and has less powder than the .357, so it is safe to shoot .38 Special from a revolver chambered in .357.
However, you can’t go the other way. Shooting .357 Magnum in a .38 Special revolver makes a hand grenade you can’t throw. Luckily, most .357 Magnum rounds won’t fit in a .38 Special because they are too long.
In semi-automatic pistol rounds, the base is the same diameter of the case. These are designed to index on the “shoulder” of the round. You will see these in calibers such as .380 ACP or .45 ACP. The ACP stands for Automatic Colt Pistol. You will also see calibers like .357 SIG, which is a pistol round designed by Sig Sauer to mimic the ballistics of the .357 Magnum revolver round.
You will also see some oddballs, like .45 GAP (which stands for Glock Auto Pistol). This cartridge is very similar to a .45 ACP, but the case is about a quarter-inch shorter. It was designed by Glock to mimic the ballistics of .45 ACP +P in a shorter case, which allows for smaller grips.
I just mentioned something else. +P is a designation for a round with extra pressure. The Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) was created to make an industry standard for ammunition. So, if you buy Federal 9mm and Colt 9mm and Winchester 9mm, all of those rounds meet SAAMI standards. That way everything is the same and same. There is a window for each measurement of ammunition manufacturing that must be met.
That includes internal pressure resulting from firing a cartridge. Most rounds are made to the low end of that acceptable window, but some self-defense rounds are made to the higher end for more stopping power. Those will be identified with the +P label.
Firing a steady diet of these through a firearm not rated for them will cause extra wear and tear, and possible failure (potentially catastrophic failure).
Always check with your firearm’s manufacturer to see if your gun is +P rated, not your local gun store. Not because they don’t know, but because it may void your warranty.
Some revolvers are chambered in semi-automatic calibers. I have shot 9mm, 10mm and .40 S&W revolvers. Remember when I said that pistol rounds will drop through the cylinders of revolvers? To prevent that, there is a special adapter called a moon clip that hold the rounds in the cylinder. Half-moon clips hold three cartridges; full-moon clips hold six.
You will also find revolvers chambered in shotgun calibers. The Taurus Judge is a popular one as it is chambered in .410 (and also fires .45 Long Colt). This works great because the shotgun shell has a larger rim, just like a revolver cartridge.
Shooting the proper ammo is essential. You want something that feeds and cycles reliably. But most importantly, you want the right caliber because the wrong caliber at best won’t work — and at worst can cause you great harm or death. If you ever have a question about your firearm’s caliber, take it to your local gun store so they can look at it and determine the proper caliber.
And yes, you need to physically take the gun in to them so they can put their hands and eyes on it. Calling them and saying, “I have a Springfield Armory XD and I need to know what ammo it uses,” doesn’t help because that particular model was chambered in 9mm, .40 S&W, .357 Sig, .45 GAP and .45 ACP.
Again, you just asked me for tires for your Chevy. Chevy makes Corvettes, Suburbans and Aveos. If I don’t know exactly what you’re driving, I can’t help you.
Capt. Cayle Wills is a salesman and gunsmith at Higher Power Outfitters (1826 Tamiami Trail, Punta Gorda). Contact him at 941-916-4538 or Cayle@HigherPowerOutfitters.com.