Best AR-10 Calibers: Power Packing Rounds for Hunting & Competition

The AR-10 platform has exploded in popularity within the past decade as more and more people seek a semi-auto rifle with improved range, hitting power, and accuracy.

If you’ve found yourself looking to jump onto the AR-10 train, you’ll quickly realize that this platform has an almost paralyzing number of calibers to choose from.

So, which do you choose? How do you know what the best AR-10 calibers are?

The Quick List

• .243 Winchester
• .260 Remington
• .308 Winchester
• 7.62x51mm NATO
• .338 Federal
• 6.5mm Creedmoor

What’s the Difference Between an AR-15 and an AR-10?

Before we determine the best AR-10 calibers, it’s best to start by answering the AR-15 vs. AR-10 question.

The company Armalite was birthed in the 50s, shortly afterward pitching their AR-10 rifle (chambered in 7.62x51mm) to the U.S. Army for adoption.

The Army decided they wanted a smaller round and lighter gun; thus, the AR-15 became the most popular battle rifle in American homes today rather than the AR-10.

Visually, the rifles look the same, but the food is different here. AR-15s shoot the iconic 5.56mm round, while AR-10s are now typically chambered for the much larger .308 Winchester.

It’s a result of being designed for larger rounds that the AR-10 can shoot further, more accurately, and with more impact than an AR-15.

8 Best AR-10 Calibers

.243 Winchester

A very popular cartridge, you’ll typically have little problem finding .243 Winchester on gun store shelves.

Though it’s not as good as .308 Winchester for long-range accuracy or hitting power, it serves as a very nice cartridge for the light-framed shooter looking for something with a bit more oomph behind it than an AR-15.

The reason for this is the decreased recoil. You can shoot an AR-10 chambered in .243 Winchester without feeling as if a mule has repeatedly kicked you by the end of the day. It makes for a darn good deer cartridge as well.

.243 Winchester

$30

at Lucky Gunner

Prices accurate at time of writing

$30 at Lucky Gunner

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Perchance your locale bans hunting with .22 caliber bullets, an AR-10 chambered in .243 Winchester can make a very nice alternative to a traditional AR-15.

Just know that if you were willing to step it up to .308 Winchester, you’d end up with less wind drift and further reach.

.260 Remington

You’ll notice that a lot of AR-10 cartridges are just different flavors of the .308 Winchester. The .260 Remington is one of those, being a .308 Winchester necked down for a .264 bullet.

You’ll still get excellent long-range ballistics with these cartridges (in many cases better than .308 Winchester), but with the added benefit of reduced recoil compared to a .308 Winchester as well.

A .308 Winchester really isn’t that bad, to begin with, but if you’re talking about hour after hour spent at the range or a lighter-framed individual, every decrease in recoil helps.

.260 Remington

$29

at Lucky Gunner

Prices accurate at time of writing

$29 at Lucky Gunner

Prices accurate at time of writing

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You have to be careful with over-penetration with these cartridges, though, so keep that in mind if you’re thinking of using these for self-defense purposes.

.308 Winchester

Ahhh, the classics.

This is easily the most common caliber you’ll find an AR-10 chambered in and is a classic for a reason: it rocks. For proof of such, just look at how prevalent this cartridge is.

It’s likely to be one of the most popular hunting cartridges in the world simply because it does fantastic for such a large gamut of issues.

Snipers use it, hunters use it, and you can even find the occasional PRS shooter using it as well. With a .308 Winchester, you can easily harvest deer, wild hogs, elk, and black bears.

I’ve heard reports of other guys using this caliber on the bigger bears with success, but I’d personally want a .30-06 Springfield for things that could easily eat me.

It’s hard to go wrong with a .308 Winchester.

Remington Premier .308 Win 168gr MatchKing BTHP

$24

at Lucky Gunner

Prices accurate at time of writing

$24 at Lucky Gunner

Prices accurate at time of writing

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7.62x51mm NATO

This is what the original AR-10 was chambered in. If you ask around, you’ll find that a lot of guys shoot these out of their AR-10s chambered in .308 Winchester.

If you try to shoot a .308 Winchester in a barrel chambered for 7.62x51mm NATO, you could soon end up with fewer fingers on one hand. 

7.62x51mm NATO ammo is plentiful and shoots with similar ballistics to a .308 Winchester round. This, in turn, means the 7.62x51mm NATO can serve as a fantastic hunting cartridge for even many larger animals.

7.62x51mm

$20

at Lucky Gunner

Prices accurate at time of writing

$20 at Lucky Gunner

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.338 Federal

This is a .308 Winchester which has been necked up to accept a .338 bullet. There are pros and cons to this. For starters, you will end up with a bigger bullet hitting your target. A lot of guys out there like using this for bears, moose, caribou, and elk as a result.

It can still easily handle hogs and deer as well, though, if that’s more up your aisle. That bigger bullet comes at a cost, however. Compared with the .308 Winchester, you will see diminished range and more bullet drop.

.338 Federal

$59

at GrabAGun

Prices accurate at time of writing

$59 at GrabAGun

Prices accurate at time of writing

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So, no, this isn’t the best long-range cartridge, but if you want your AR-10 to hammer away at things within 300 yards with a bigger bullet, these can serve the trick.

6.5 Grendel

It seems as if, right now, any cartridge with a 6 in front of it is common at PRS events, with the 6.5 Grendel being no exception. It’s still not as powerful or accurate of a round as the .308 Winchester (particularly when wind is involved).

Still, it does have one bonus a lot of shooters will be interested in: about 2-3x less recoil than a .308 Winchester.

If you’re looking at a situation where you’re dumping mags and need accurate fire (think hog hunting), lower recoil can drastically improve your shot placement.

6.5 Grendel

$21

at Lucky Gunner

Prices accurate at time of writing

$21 at Lucky Gunner

Prices accurate at time of writing

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Should you be more interested in large game, though, you’ll want to find something bigger.

6.5mm Creedmoor

Another cartridge that’s really gained steam within the PRS world, the 6.5mm Creedmoor serves as a fantastic chambering of the AR-10. And why has it performed so well in PRS? Because the long-range accuracy you can get with a 6.5mm Creedmoor is superb.

In many cases, it’s better than .308 Winchester.

While it doesn’t have the kinetic energy that .308 Winchester does, it still stays supersonic out to roughly 1100 yards and can serve as a very potent deer harvester. And all this with reduced recoil. If you’re pouring lead down range rapid fire, your follow-up shots will take time to line up.

6.5mm Creedmoor

$22

at Lucky Gunner

Prices accurate at time of writing

$22 at Lucky Gunner

Prices accurate at time of writing

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For more info on the 6.5mm Creedmoor, check out our in-depth guide HERE.

7mm-08 Remington

This is a .308 Winchester case necked down for a 7mm bullet, and – if you can find one – serves as an awesome AR-10.

Most of what I see out there are typically bolt-action rifles in 7mm-08 Remington, but if you can find an AR-10, you’ll end up with a rifle with a very flat trajectory, a high degree of accuracy, less recoil, and report than a .308 Winchester, and that can handle a heck of a lot.

Deer, black bear, moose, elk can all be handled by a 7mm-08 Remington chambered AR-10. Obviously, you would want heavier bullets for the bigger stuff (around 160gr for moose).

Finding ammo won’t be the difficulty you’ll have here, as this has been around for quite some time. It’s finding the rifle which will prove to be a challenge. 

7mm-08 Remington

$44

at GrabAGun

Prices accurate at time of writing

$44 at GrabAGun

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Prices accurate at time of writing

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How Do You Choose the Best AR-10 Chambering?

The same way you choose the best tool for any other job: you consider what needs to be accomplished.

There are three main camps you’ll find people falling into when they’re looking at purchasing a weapon: for self-defense, hunting, or competitions.

We could even break hunting down into big-game hunters and medium-sized game hunters here.

Out of all these, what do I think is the best? Here’s my take…

Self-Defense

I’d stick with the classics here, and that’s why I would choose .308 Winchester if my sole intention in buying an AR-10 was self-defense. My main reasons for this are due to how easy it is to get this ammunition compared to a lot of these other cartridges.

I can find .308 Winchester pretty much every time I walk into a gun store around here, and the sticker price won’t make me gag.

In a fight, you fall back onto your level of training, and the easier/cheaper you can find ammo, the easier/cheaper it is to train. More training opportunities make for a better self-defense gun for me.

Sure, some supercharged, exotic round may sound cool, but if you were only ever able to find or afford a minimal amount of ammo, you quickly find yourself with an expensive stick in your hands once you burn through it.

Hunting

Really, I think 7mm-08 Remington is one of your best bets here, regardless of whether you’re hunting the bigger stuff or whitetail deer. It can handle them all.

I like regular .308 Winchester here as well, but I like the idea of something just as tough but with less noise to it.

If I’m at the range, I have all kinds of ear protection. When I’m hunting? Ehh, typically not. I’ll take any advantage I can get when it comes to a lower-decibel round for work out in the woods.

Competition

To me, this is a no-brainer. I’d choose 6.5mm Creedmoor.

Yeah, there are a lot of other cartridges within this 6mm ballpark that are pretty sweet as well. I get that.

But from our list above, 6.5mm Creedmoor is my favorite for dead-on, competition-grade accuracy. There’s a reason this is so popular within the world of PRS – it wins medals.

What Are Some Other AR-10 Calibers Out There?

Still looking for more?

You can find a manufacturer out there willing to make an AR-10 (or an AR-15, for that matter) out of just about any caliber out there.

If we’re looking at AR-10s, these are just a few more possibilities you’ll see on the market besides what we’ve chosen…

• .243 Winchester
• .260 Remington
• .300 SAUM
• .300 Winchester Magnum
• .308 Winchester
• .338 Federal
• .338 Lapua Magnum
• .358 Winchester
• .45-70 Government
• .458 HAM’R
• 6mm Creedmoor
• 6mm ARC
• 6.5mm Creedmoor
• 6.5 Grendel
• 7.62x51mm NATO
• 7.62x39mm
• 7mm-08 Remington
• .30-06
• .500 Auto Max

Final Thoughts

An AR-10 is a fantastic weapon, and I think it’s saying something when you consider that it wasn’t the AR-15 that Eugene Stoner pitched to the Army first – it was the AR-10.

If you’re debating as to whether or not you should delve into the world of AR-10s or not, I would say go ahead and take the plunge (before you can’t).

Are there particular cartridges you prefer over others? What has been your experience? Let us know in the comments below! Looking at buying your own AR-10? Check out our guide on the Best AR-10s.