And now for the final column in our ammunition series: Rifle ammo. No, I didn’t save the best for last; in fact, rifle rounds are kind of boring. And relatively simple. And pretty much unchanged since their inception. And did I mention boring? But maybe you’ll learn something.
Rifle rounds, like pistol rounds, may be measured in either inches decimal or metric. You will see both .243 and 7mm. Where rifles can get confusing is in their naming conventions. While .243 and 7mm are self-explanatory, what exactly does .30-30, or .30-06, or .22-250, or 6.5 Creedmoor mean? And you can get even more confusing. For example, .300 Weatherby, .300 Winchester Magnum, .300 Remington Ultra Mag, or .300 Blackout sound similar but are completely different rounds.
Rifle rounds were essentially the first modern cartridges made. Most ammunition was made by the same company that made the rifles and there weren’t many of them back then, so competition was fierce. This is why you will see cartridges like .243 Winchester. That cartridge was invented by the Winchester company, but today you will see Remington and Savage rifles chambered in .243 Winchester.
Some naming conventions were for competitive reasons and some were actually for simplicity. The .30-30 was both. Winchester created the .30 WCF which was the forefather of the .30-30. Then, when Marlin started chambering rifles in .30 WCF, they renamed the cartridge to .30-30. The first .30 was for the .30-caliber bullet, and the second 30 was for the 30 grains of powder used in the cartridge. Voila: .30-30.
The .30-06 (pronounced “thirty aught six”) is much simpler. It has a .30 caliber bullet and it was created in 1906. But where does something like 6.5 Creedmoor get its name? Well it uses a 6.5 mm bullet and was created by Hornady for Creedmoor Sports.
The .22-250, which is a so-called wildcat round, takes its name from the caliber of the bullet and the parent case. It uses a .224 bullet stuck in a .250-3000 Savage case that has been necked down to accept the .224 bullet. Most wildcats work that way: Stick a smaller bullet in a larger case to get a faster, flatter ballistic profile.
But not all. Rounds like .300 Blackout are just the opposite. Here, a .30 caliber bullet was shoehorned into a 5.56 mm case. Advanced Armament Corporation originally created the .300 Blackout for the military. Our soldiers were kicking in doors in Iraq, and the .300 Blackout was designed be fired out of a suppressed rifle and to limit overpenetration. The walls in most houses in Iraq are very thin, and it’s possible to injure people next door.
5.56 is what most AR style rifles are chambered in and what the military uses in its M16A2 and M4 rifles. Changing a rifle chambered for 5.56 to fire .300 Blackout ammo requires only a new barrel, minimizing effort and expense.
For once the military leadership showed a little common sense and asked what would happen if during one of these urban raids, the enemy decided to mount an attack from 500 yards away, well outside of the .300 Blackout’s effective range. So our soldiers kept on using the 5.56, despite its limitations. Luckily for AAC, the civilian market latched onto the .300 Blackout and it has become popular. Personally, I don’t like backwards wildcat rounds. Putting a bigger pill in a smaller bottle makes no sense to me.
Next, you will see grain measurements, similar to handgun rounds. This is simply the weight of the bullet you are shooting. Bullet weight affect rifle accuracy more than pistols simply because you are shooting rifle bullets further. When zeroing in a new rifle, you should use several different grains of bullets to see which is more accurate.
This can be dependent on several things like rifling ratio, barrel length and even atmosphere. The .224 Valkyrie round is advertised to hold supersonic speeds past 1,000 yards. However, it was tested in Denver, Colo., where the air is thinner. Will that round hold supersonic speeds past 1,000 yards in the pea soup we breath here at sea level? No way.
Then you will see designations on bullet type. While we talked about handguns using FMJ (full metal jacket) and HP (hollow point), rifle rounds have a handful of bullet designs. You will see FMJ and HP in rifle rounds also, but you will also see other designators like FMJ-BT. BT stands for boat tail and is used to improve accuracy in some calibers for medium to long ranges. You will also see SP (soft point), which has an exposed lead nose that helps with expansion.
If you’re looking at lever action calibers like .30-30 or .35 Remington, you’ll notice that those bullets have a flat nose on them. That is because they are loaded into a tube magazine front to back. If you used pointed bullets, each point would be sitting against the primer of the round in front of it, and so forth throughout the tube magazine. Guess what happens if you say, trip and fall and break your fall with the butt of your rifle? BOOM! All the rounds go off at once in your magazine, and your hunting days are over. Actually, all your days are over.
Like some revolvers, multiple calibers can be shot out of the same rifle. And just like revolvers, you have to be careful with this. The most popular is 5.56mm and .223 Remington. Most AR style rifles are chambered in 5.56mm, which is a NATO round. But you can also fire .223 Remington out of 5.56mm chambered rifles. They are so similar in design that it is fine to do this.
However, you don’t want to fire 5.56mm rounds out of a rifle chambered in .223 because the allowable pressure of the 5.56mm is higher. There is a recently developed chambering called .223 Wylde, which will shoot both .223 Remington and 5.56mm but do it better than 5.56mm chambers.
Just like any firearm, make sure you use the round designated on your firearm. This information is usually found engraved on the barrel. Bad things happen when you don’t, and a lot of these chamberings can be confusing. Hopefully we’ve helped with that.
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.