4 Things to Know Before Building Your AR10

bug out bag and gunThe AR10 is a powerhouse of a rifle. It is semi-automatic, magazine fed, and modular. Like an AR 15 you can build your own AR10. In fact, you can even build an AR10 from an 80 lower receiver. An AR10 is easy to build but there are a few critical things to know before you dive into it. Here are 4 things to know before building your own AR10.

1) What is an AR10?
The AR10 is the less popular, older, and bigger brother of the AR 15. Eugene Stoner initially designed the AR10 as a combat rifle, but when the demand came for a lighter rifle it shrunk to the AR 15. The AR10 is chambered in the full power .308 caliber round. The AR10 was never adopted by the United States military and never reached the same popularity as the AR 15.

The AR10 has more recoil due to its full powered round, but is much better suited for long range shooting. The AR10 is also a popular hunting rifle option, as it is suitable for both medium and heavy game. It is also extremely versatile for security and defense purposes as it a top performer at long range while boasting 30 round mags.

2) The AR10 Platform is NOT Standardized
The AR 15 is a standardized platform. Take any two AR 15s and there is a 99.99% chance their parts can interchange. AR10s are a bit different. They are not standardized for construction and different companies have different iterations of the AR10 design.

This leaves two main AR10 patterned rifles, the Armalite series and the DPMS series. When you choose your AR10 80 lower receiver you must make the decision to go DPMS patterned or Armalite patterned. Both patterns can result in a good rifle, but DPMS has a slight advantage when it comes to magazines and parts interchangeability with other manufacturers and even the AR 15 rifle.

For this reason, and more, we’ve chosen to go with DPMS patterned 80 lower receivers.

3) AR10 Internal Parts are not Always Compatible
Because of the different patterns you’ll see barrels designed for both Armalite and DPMS, or upper receivers designed for Armalite and DPMS. These parts are not interchangeable between rifles. Once you select which pattern lower to use, you’ll have to select parts that are compatible with it. This includes your barrel and BCG. If you go with a DPMS pattern rifle you must use a DPMS barrel and BCG, the same goes for choosing the Armalite platform.

DPMS pattern AR10 80 lower receivers do have more options in terms of parts choice once it comes to assembling the rifle. Going the 80 lower route also means you’ll a specific jig. The jig must be matched to the 80 lower. It’s not like AR 15s where there aren’t differences. When you choose an AR10 80 lower receiver make sure you purchase the compatible jig.

4) AR10 Lower Parts Kit
Because of small difference between lowers there are several parts that are only compatible with AR10 lower receivers. Small parts like the safety, trigger, and trigger springs can be swapped from AR10 to AR 15. Parts that will not swap are the following.

•             Bolt Catch
•             Takedown pins
•             Buffer
•             Magazine catch
•             Most Pistol Grips

The AR10 does bring the boom in terms of power and range. (And noise.) The AR10 is probably one of the most modern, and modular 308 rifles out there. Most 308 rifles are stuck in the Cold War period where the AR10 happily evolved out of it.   If you are looking for a versatile and reliable rifle for your kit, the AR10 should be towards the top of your list.


  1. Jesse Mathewson says:

    When it comes to large caliber firearms…I tend to agree with many operators and field proficient types.

    A solid bolt gun will do better for you, for several reasons.

    1. Weight- most muricans will never be able to carry a kit including ammo for a .308/7.62×51 Fal or Ar10- plus the 12lb rifle, a rem 700 or savage etc., can be had with scope for right at 6lbs
    2. Necessity, elephants have been taken and are taken regularly with 7.62×39 – so could grizzlies etc., sooo?
    3. Original intent, distance+bullet ability etc.,

    1 in 1000 shooters actually practices regulsrly at all, 1 in 10,000 past 300 yards with intent and even fewer at distances where the round shines.

    Just my two cents.

    (Additionally, cost, rarely under $1400 without good glass and without good glass, they are not really any good:(

  2. tommy2rs says:

    If you’re wanting to build a .308 Stag has an offer going on at the moment for their 10 series .308 upper lower combo. Sadly for me they don’t have a lefty version or I’d be all over this.

    Stag .308 Upper/Lower Combo *Special Pre-Order Pricing*

    Your Price:
    $349.99 (You save $60.01)
    Product Details

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  3. Bwhntr61 says:


    2300.00 bucks though! For that a guy could get a a DPMS .308 , a decent Nikon scope and a nice Glock 17/19 pistol and maybe a couple hundred rounds of .308 surplus for practice.

  4. My family and I used to do a lot of shooting with AR-15’s I have never personally shot an AR-10 but my little brother swears by them.

  5. Hello
    You mention in your post that “if you go with DPMS you must go with DPMS barrel and BCG…..”
    Not trying to nit here, but many vendors now make “DPMS Pattern” barrels and BCG’s. Nothing against DPMS components, but there are many other options compatible with a DPMS pattern rifle build.
    As far as DPMS goes, they should get kudo’s for practically developing a “standard” for the .308 Stoner package. While you are correct in writing there is no “spec.” as is associated with the AR-15/M-16, DPMS with their “open source” approach are virtually the standard spec. for this platform and folks wanting to build one. Heck, Armalite even markets an AR-10 in the DPMS pattern (AR10A for Magpul mag’s) which is their newer model.
    Prior to DPMS’ efforts, no manufacturer could even produce a .308 Stoner rifle without spending months or years in litigation over patent and copyright infringements with Armalite. And the result was a rifle with near-zero parts interchangeability with other similar platforms.
    Now, the vast majority are adopting the DPMS pattern almost as the “mil-spec” we are accustomed to with their .223 cousins.

    • Guide

      Very good points here that I was not aware of. I have been on the fence about a semi auto .308 for some time. KELTEC RFB and Sig716 were my top choices. Still wavering on it. I have several bolt action .308 rifles and really wondering what I gain with a semi auto .308. Quicker repeatable shots would be what some might argue, faster reloads, more power to penetrate cover, etc.

      One of the guys in my prep group has a DPMS in .308, 16 barrel. Seems decent enough, although he only has about 50 rounds thru it. Hardly enough to make a long term eval.

      • Jesse Mathewson says:

        Again. Purpose built, if all you are doing is hunting…stick with bolt guns, if you are that good with .308 that you need a long distance precision tool…stick with your bolt guns, test after test after comparitive real life test show no real net benefit – except that you can now say, I have a semi auto .308 🙂

        Have had several acquintances (spllg?) who can barely keep 5 rounds of 5.56 inside 6 inches at 100 yards switch to ar10 platform styled rifles, (and yeah, 50 rounds…is not really even a start) practice makes perfect…unless your willing to invest in 50 rounds minimum a month, and some solid shooting classes, why waste the money?

        • Hello
          No argument from me. Obviously, the intent here is to come up with a hard-hitting “tactical” type rifle. Having shouldered a couple different semi-auto .308’s for half a day or so, I can attest to the formidable weight involved. The range is nice, but whew! What a price to pay weight-wise, not to mention dollar-wise.
          Savage has recently offered some really nice bolt guns, chambered in .308, very reasonably priced. They get stellar reviews.
          If I’m needing more than a .223 in semi-auto and I have to carry it, (say, hog huntin’ with suppressor & night optics) I’m packin’ an accurate 7.62 x 39 platform (such as a SIG 556R or AR-47) and handloads.

          • Axelsteve says:

            The ar 10 is pretty spendy. For the money a m1a would keep me pretty happy. Put a synthetic stock on it and that would carve off some weight. The 270 may be a consideration if you want flat shooting and long range.Not a nato round but so what.

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