What Caliber Does an AR-10 Shoot?


When considering the AR-10 being glass sight mounted or iron sights, It is advisable to also consider which chambering you’re going to obtain in this rifle.

For the most part, 308 Winchester is the gold standard for the AR-10, being the civilian variant of the long receiver Armalite rifle design. After the 308 is considered, everything else tends to fall in at or above this cartridge case length, and that is because the AR-10 is a longer receiver design.

Because the development of the long receiver AR-10 was based on the 7.62×51 (308 Winchester) and developed as the M-10 for the military, which made it an outstanding unit sniper/sharpshooter rifle that was spot on accurate to 800 yards, the receiver design has caught on as a multi-caliber offering by many manufacturers building this variant of the ArmaLite (AR) series rifle.

.243 Winchester – A Flat Shooter with Low Recoil

With a cartridge making use of the 308 basic rifle case, it is not hard to fit a number of different cartridge types into the magazine setup, and also the basic receiver of the AR-10.

One very popular round that fits this description is the 243 Winchester in the 308 and necked down to a 6mm bullet. Keeping the cartridge case rim size the same on both rounds, the building of the 243 Winchester into the AR-10 is a piece of cake regarding how a firearms manufacturer of AR’s sees the problem.

Choosing the Best Cartridge for You

The rest of the story is whatever crosses your mind. Some manufacturers and custom shops will custom chamber almost anything you want in the standard AR-10 rifle.

The only rule that applies is if the round can be accepted in the magazine well of the AR-10 receiver and if the cartridge can also be handled with the bolt face and receiver/chamber length offered by the ArmaLite design. If the cartridge is too long or carries a greater circumference than the 308, some significant adjustments will need to be made in the receiver design.

One example of this is the use of the 30-06 Springfield and the 300 Win Mag in the AR -10 pattern rifle. The end product, in this case, is a special build that is again longer and carries more receiver strength to deal with the heavy-hitting rounds.

As for cartridges that fit the normal mold that will not require a special off-track build regarding the AR-10, some examples of these are in the following guidelines. Also with this group of cartridges are some of the most favored by hunters and target shooters alike.

6.5 Creedmoor – Long Range Precision

As a start toward the general use search, the first of the many comes up as the new and very popular 6.5mm Creedmoor. This is a round that came from the 30 T/C and 308, depending on how you asked. The round is effective at 1000 yards or beyond when altitude is considered and based on my observations and the fact that I have taken trophy class whitetail to 540 yards with the cartridge in the 142-grain bullet. Therefore, I have nothing but admiration for this choice when considering the AR-10 as a hunting tool.

7mm-08 Remington – A Well-Balanced Wildcat Option

In some circles, the outstanding 7mm in the 7mm-08 is another choice that is an easily applied cartridge. The 7mm bullet is a well-balanced projectile as applied to a hunting rifle. With low recoil and excellent accuracy, the AR-10 would look quite positive as a selected gun cartridge combination.

.300 Winchester Short Mag – Big Punch in a Small Package

With more power, the 300 Win Short Mag (WSM) is a good choice being it is designed for a short action turn bolt rifle and is a natural fit as applied to the AR-10 receiver. In the same area, the 300 Remington Short Mag is also in this ballpark as an option, and take on the .338 WSM and .260 Rem, and you have quite a selection of hard-hitting big game rounds to consider.

The Heavy Hitters

Roll into the big guys like the .416 Win Short Mag and others in the big 45 caliber department, and you soon will realize that the AR-10 is a do it all system with a super simple breakdown and total systems design. Built in two primary pieces, the AR-10 is simple to maintain and easy to build into almost whatever you want to shoot and can be held within the framework of a reasonably priced firearm.

My Rifle Recommendation

AR-10 With Rounds on the Range

My first choice in these rifles is the Ruger SR 7.62, which is a very high-grade rifle, and one pile of bang for the buck. I have put this rifle in the hands of my associates, and close hunting buddy’s here at Ballistics Research & Development with outstanding success afield.

The Ruger AR has been a solid test base for new loads, bullet designs, and other related shooting products when afield. Chambering in these guns has been 308 Win and 243 Winchester for the most part. These rifles also cover 20 years in terms of field use. Therefore the cartridges being applied are old school gold standard in the short action high power cartridge group. 

Of late, the US Army has been considering making some changes in both cartridge types and base weapons designs. However, the AR-10 in the M-10 has served the military well for a very long period. As of now, I fully expect the AR-10 to do a standup job in the area of sporting rifles again for at least another decade or two without question. 

Also, if you want to add a scope on an AR-10, Hunting Mark reviews will help you choose an AR-10 rifle scope that would be best for your money.

Thanks for reading!

For more, check out 9 Ways to Serve Your Country Without Being in the Military.

Loyal Brezny

L.P.Brezny has been writing for the past 50 years. He has authored four books on shooting with three on long-range, and one covering shotgunning.(Amazon) With 26 years in a metro police department as a street officer and the rank of SGT / training L.P. has covered all the bases regarding weapons and street survival. You can find more about Loyal at https://huntingmark.com/.

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