Looking at building an AR10 in 260Rem. Wondering if anyone has a recommendation on complete uppers and/or seperate upper & bbl manufacturers. Also anyone that has done this and has any advice throw your 2 cents in.

How much AR building experience do you have?

Not a poke at you, the AR-10/SR-25 platform is not standardized like the Ar-15 world is. You can sink a doctrinal butt-load of money into parts that will not interchange.

You need to decide what standard you want to use before buying parts for a build.

Armalite is "the" AR-10 design, and does not interchange uppers with DMPS lowers, and the reverse. Several companies make parts/barrel for these rifles, but they tend to be higher priced parts, IMHO.

DMPS is the common SR-25 platform, and has a decent selection of aftermarket parts that in the working man's price range. They sell a complete .260 upper if you can find one, but you need to use their lower. Remington, CMMG, and others follow this design. Probably the easiest to get "common" parts for from other than DMPS sources.

RRA makes a quality (LAR) big AR, but the upper/lowers do not interchange with other brands. They offer a .260 upper as well. Their upper is a ~.25 inh longer than others, will not interchange with other lowers that I am aware of. The rifle uses FN-FAL magazines.

The SW MP-10 is yet another rifle with a slightly different set of standards, as the uppers/lower/BCGs don't interchange with others.

The biggest things on an AR-10 sized build is the time to invest in the parts search and the amount of money invested, once you pick a brand/design to start the build with, you are committed without another major investment if you change gears in the middle of the build. JMO.

Mega MATEN receivers
Lilja barrel
JP enhanced bolt

The rest is up to you.

Keep in mind a AR-10 is not the same as a .308 AR based off the SR-25/DPMS style rifles. The parts do not all work together.

RRA does NOT offer a 260 anything. if they did, I would have bought an upper to go with my 308 LAR-8. My brother has a RRA .243win and they at one time also offered a 7-08 upper.

I don't see them listed on their website, probably because the huge demand for the more standard calibers like 308, .223, 6.8spc. maybe when things calm down they will offer some new uppers for the LAR-8 lowers. I'd love a 260 and 358win upper, and asked them about making them a few years ago.

I would love a 358win for mine as well...

Maybe not recently, but I've seen one .260 barrel that was at least mated to a RRA upper, and stated to be factory.

Given the state of selling last year and the desire to make a profit, who knows, the vendor was selling it as a factory build.

Can't tell you how much I appreciate the input. I have a friend that has a really professional gun smithing/custom shop and I think he is going to get the bulk of the work. We are back ordered on the lower right now so I may be coming back again later for more advice.

Which lower did you decide to build on?

I do not like where the mag release is located on a LAR-8.

The .308 based AR platform is moving towards the SR-25 style receivers. IMO, it would not be a good idea to buy something that uses proprietary magazines, parts, and little to no aftermarket suport.

???????

It's in the same place as EVERY OTHER AR TYPE GUN.

The RRA Bolt release is in a different spot, but in all reality it's where all the other ARs should be too. Having it on both sides of the trigger guard makes it easy to get to without having to remove your hands from the pistol rip or forend.

Haven't responded as I haven't checked the computer for a few days. I am looking at 80% lowers and learned an acquaintance has experience in building 15's and at least one 10, plus he has access to a machine shop. I am now looking at uppers with complete bolt groups but without bbl's. Any thoughts? I am thinking of a lilja bbl or maybe a krieger bbl. Still researching the platform and leaning towards DPMS or RRA. Some stuff I am reading seems to indicate the Armalite platform is tough to get parts and support for. Is this true? I have to say this is giving me a headache. I have decided when all is said and done I am going to decide on the platform and get all of the parts before we even start to work on the lower.

After all of that I finally found some articles on AR10 builds that helped me make sense of it. after a little more research it looks like I am going with the DPMS platform if for no other reason than the availability of parts, including after market. It will be a couple of months before the lower gets here so this is probably going to be a summer or fall build. If anyone has any info that might change my mind, fire away. All options are open until the machines are turning.

Maybe I missed it but why go through the trouble of finishing an 80% lower. There are several matched receiver sets available that are very nice and compatible with SR-25 / DPMS parts OR AR-10 parts (magazines are still SR-25).

Building one to what I want is something I've always wanted to do. The 80% build has no S/N.

If you decide you want a ready to go upper let me know. I have been thinking of selling my 20" stainless .260 upper. I never shoot it and it just sits in the safe. It's super accurate with the 123 AMAX, but I usually shoot .260 in my bolt guns and run 308 in the gas guns because I have lots more brass.

I went with a complete DPMS upper. At the time I didn't know enough about AR's to piece one together. That being said I can only get marginal accuracy (1.5") out of mine. I feel the production barrel and trigger, along with my inability to get a consistant cheek weld are the problems. IME stick (extruded) powders don't work. I'm going to try several ball powders and use a Tubb's fire lapping kit.
The DPMS is an 8.5" twist, I would recommend an 8".

Nothing wrong with 80% receivers - no paper trail is a good thing!!

Well, it's been a few months but I finally decided to go ahead and build the 260. I have ordered the lower and have to wait 3 months. I am interested in any uppers, Barreled or not. I am going with the DPMS style. I don't have an unlimited budget but want to build as good a one as I can. If you have any recommendations about uppers, bolt carriers, etc I would love to hear about it. If you have something for sale please PM me.

Bob,

Did you get a complete lower, or a stripped? Enjoy the build, the result will be worth the wait.

I ended up ordering a northen precision 80%.