I'm looking at building/getting an AR-10 at some point just because. I understand that there are several makers just like the AR-15 but not all are compatible with each other. Can someone explain to me what the most popular/available variants are so I don't end up getting the Studebaker/Edsel of the AR-10 family instead of a Ford/Chevy.

I have two Armalite AR-10's, and they are good rifles, but use proprietary mags.

Armalite now builds lowers that accept PMAGs, and if I were starting from scratch with a .308 AR, I would go that route

The AR-10 is not a govt rifle-it's a commercial gun, so making proprietary parts is a good thing from a marketing view, if it breaks; you have to buy "MY parts at MY prices".

I picked an MP-10 up last year, and ran a boxes of rounds through it. Shot OK with the factory magazine and the 20 round Pmag. I did LIKE the rifle, as it has an ambi safety, mag release, and bolt release from the start. It's also a bit lighter than the DPMS rifles, and has an 18 inch barrel.

I ended selling as the accuracy was pretty steady at 1-2 inches, and not much room for improvement without a major re-build.

Couple of points on the Smith, it was close, but mine was NOT DPMS compatible. The upper pin lugs were longer on the Smith than the DPMS rifles. My Smith upper would not close on a DPMS lower without some fitting, I believe the rear lug is wider to prevent the installation. I don't know what the gap would be between upper and lower, we didn't go that far once the rear lug clearance was identified.

A DPMS upper would close on the Smith lower to about 30 degrees, maybe a bit less, and then you could feel the metal-on-metal bind of the shorter DPMS front lug against the Smith lower. The upper would not close any further without forcing it.

RRA rifles - Up front, I do like RRA rifles in 5.56. The .308 line is a another rifle that only fits RRA upper and lowers, in other words, it's own company parts. Read the parts disclaimer on the RRA website.

The RRA takes FN-FAL mil-surplus magazines, and they make their own. The RRA marketing thought in 2005, after the first Assault Weapons Ban 94-04 expired, was to design a rifle to use a surplus magazine that is available world-wide, think World War Z and cheap magazines.

The FN FAL magazines can hit/miss on quality, think South Africa manufacturing vs. German engineering -you have to know what you are buying.

RRA uppers are about an inch longer in length than DPMS pins, so they will not mate up.

Because the FN-FAL magazines latch differently, the magazine release is forward under the trigger guard. It also serves as the bolt release. Operators claim it works fine, but I would have to retrain between rifle controls, hard to break 25 years of training on AR rifle, less of a problem on other designs.

Armalite - separate rifle, with its own specs and parts. The Armalite uppers will mate with a DMPS lower, BUT they have an angled cut on the back of the upper that leaves a gap at the back of the upper receiver that exposes the buffer/bolt rear. The same cut prevents a DPMS upper from mating with an Armalite lower.

Most Armalite parts are NOT compatible with the DPMS rifles, especially bolts and carriers.

DPMS - IMHO, the "Chevy" of the AR-10 world, more produced, more copied than any other. Doesn't make it the "best", just the easiest to work on, get parts for, upgrade, etc.

Remington, DPMS, CMMG, AR-Stoner, and "most" aftermarket parts company provide parts in the DPMS pattern than any other. IMO, this is the best choice for a truly unique build that is "yours".

The real wrinkle in all of this is the BCGs. I haven't found/experimented with the bolts enough to say whose bolts fit what .308 gun.

Rule of thumb: stick the same BCG as the upper/barrel, should prevent the most amount of problems.

what about the Ruger SR-762? It shoots pretty good.

I leave that post to your expertise, I've only handled one.

We've shared the same issues with the DIs, so you are way ahead of me.

great info

I'll throw in - a lot of the newer .308 AR's seem to come with 16" barrels. Let me caution you that a 16" .308 is an acquired taste. They are very loud, especially if they have a brake. When I started shooting mine at the range, it would usually have people clearing out around me, if they weren't complaining.

I eventually put an 18" barrel, and a Vortec flash hider on one of the AR-10's, which makes them more tolerable. The other one is a bull barrel 20" gun.

I have plenty of mags and spare parts for mine, but eventually I will get another gun, that can use PMAGs. Colt builds one, the LE901, that can accept standard AR-15 uppers, but I have not seen one for sale in a while, and the .308 barrels are all 16". When I buy one I'll probably ante up for a LaRue, LWRC, or similar rifle. It may or may not have a piston upper.

Sounds like it's all pretty well covered above. One thing to for me is the importance of a lower that takes Pmags, which means mostly DPMS pattern rifles.

One other thing to note is there have been variations in the DPMS pattern (different generations?) so that not all DPMS uppers and lowers are compatible with each other.

Regardless, it's wise to plan on buying both the upper and lower from the same place, and follow their recommendation on which BCG to use.

That is a good point, DPMS now has Gen 1 and Gen 2 versions of their rifles.

jimmyp has some knowledge and experience on these, but the two Generations are NOT interchangable from what little bit I know.

I think even among the older "Gen 1" DPMS stuff there were differences though. One place I read there were about 6 different variations in uppers & lowers, but I don't know if that's true or not.

I do know that some Gen 1 DPMS uppers fit my Palmetto lower, and some do not.

Thank you gentlemen very much. I'm sure there will be more changes by the time I get mine but at least I'm far more informed than I was. What prompted this was a DPMS complete upper for $700 on a Midway flyer and I was thinking that if you could put together a lower it might be a cheap way to get into one.

tmax, there is a great gob of information available. A lot of different manufacturers and some significant incompatibilities as there are no common agreed upon specifications.
You can, if you look around a bit, get a complete factory 308 AR for less than $1000. And, since it's all from one place it should at least work.

Or, you can read a lot and buy parts that are probably compatible and build.

A good rule of thumb for 308AR's is to buy the upper and lower together as a set. I recommend MEGA for receivers. They have always made top quality stuff and stand behind it. Their receivers mate well and have a tension screw to lock them together rock solid.

These things are not AR-15's and generally take a bit of learning before they run like you want them.

Just adding a couple of cents also.My overall experience is low, but I acquired a Fulton AR-10 equivalent based on the DPMS studs. Its a bit finicky but fantastically accurate. So when a bit later I found a Graf's special on a 308 upper, I bought it as a practice barrel assembly. Well, it also shoots much better than could be expected. It is exemplarily reliable also. The gist is that they interchange easily, use P-mags and have no functional issues between the two combinations.

DPMS the older Gen1 seems to work at least for DJONES, myself and RickiD sent our Gen2's back into the factory. We both had the hunter model Gen2. I got my money back, RickiD is still waiting after a bunch of months for some resolution.

I now have a Ruger SR762, its pretty good for 5 rounds, these things are a rule unto themselves. My latest go around with it was popped primer from my hand loads, which jammed the bolt closed. Right now it has the 1-6 VX6 on it and I am in the process of exchanging the scope mount.

I think the barrel is tighter than my Kimber 308 montana, however it is pretty accurate. Again after a Smith MP10, DPMS Gen2, Ruger SR762 I can unequivocally say these things are just a lot different than AR15's.

Large frame projects are just that, projects. They go on forever in time and cost and you'll likely never be happy at the end of the day. If you've got time and money to burn, your in for a ride.

Yep. By the time you get it "right," you could have just bought that $4,500 KAC. they are fun though.

I like the piston in the Ruger, but forget the crap about piston vs. DI. You loose a primer in the cogs where da bolt be going, and its locked up tighther than dicks hat band.

Love my Lewis Machine and Tool. I had an R25, but otherwise would have bought the DPMS G2. Nice guns and my limited usage at the range performed well.

I am a fan of the POF and Mega upper/lower combo. POF is strictly dPMS style platform. The Mega you can build either DPMS or AR10 style. BCG and barrel extension must be the same platform.

I hear good things about the DPMS Gen II platform as well.

Armalite stands for what is right.


http://www.gunssavelife.com/?p=5907

I know two of the DPMS gen 2's that were fubar.

I had hoped you were banned.

I've been 100% satisfied with my Aero Precision build and plan to do another or three.

Why would I be banned for holding the same positions as the average member here?

I heard it was a game changer!

Also, if able to, look at Windham Weaponry.