If you are simply looking for the most accurate complete AR-10 or 308AR you have 2 great options I can speak about from personal experience: The GAP-10 and JP Rifles' LRP-07. Both companies tune the rifle very well, which is more important with an 308 AR than it is with the AR-15 system. GAP uses maybe a better barrel, JP may tune the rifle a touch better, but with only having shot one of each for a limited number of rounds (under 2000), I don't feel comfortable laying that down as a hard fact. I am comfortable saying both are great rifles and you need to be a truly excellent gas gun shooter to every be held back accuracy-wise by either. You need to shop long and hard to make your own rifle better. For a step down in accuracy, but still a gun that you will likely never outshoot, you can check LWRCI and LMT.
I am currently building (slowly) 2 different 308 AR’s. I have a Tactical Machine lower that I paired with a DPMS upper and a JD Machine paired upper and lower set. The current plan is to make the TM/DPMS set into a 16in weapon with collapsible stock, using a cheapish barrel. The JD set is going to be an 18in barrel, probably a Lilja and most likely with a magpul PRS stock and monopod. I want to test cheap 16in barrels as I have been very impressed with the accuracy of the Larue OBR 16in. I am curious to see if I can duplicate the results on my own build but for less money.
That is not to say that LaRue uses cheap barrels, just that I am surprised at the accuracy of their barrels considering the length.
Again, I will update this page as the builds go on, but right now my initial impressions on each part are below:
The machining is professional as is the finish. Overall I am pleased with it, especially for the price. The customer service was excellent when I ordered and they shipped it to my FFL fast. They allowed me to order it like a non-firearm part but then they contacted me immediately for my FFL info. My only issue so far is that the bolt catch pivot pin, like other 308 AR’s, only has access from one side. Rather than tapping the hole to allow the normal AR-10 style threaded pin, it just has a drilled hole that accepts an AR-15 pin. It fits well, but if I ever want to replace the bolt catch or spring, I am going to have to drill out the pin as I can’t just tap it out the other side like you can on an AR-15. However on the plus side, I put it with my DPMS stripped upper and the fit is absolutely perfect. The takedown pins slide in with a little too much friction (due to the finish on the TM lower) but there is no play whatsoever between the upper and lower. It may be a fluke, but from looking and the machining of both, I think if I ordered another of each they would fit the same. Due to the extra length on the rear of the lower, I put the rear takedown detent spring and it just disappeared in the hole, so I cut another spring in half and put that in there also and it worked well. I intend on posting pics of that.
I like the concept of the logo going over both parts and uppers and lowers being paired and initial reviews (there are not too many that I could find compared to some parts) were good. I called and ordered a set and the customer service was helpful and friendly. I had a few issues with shipping and shipping dates, but they met the deadline I had told them I needed the parts by - due to my only being home for a limited window. The machining is excellent as is the finish. The upper and lower do not fit together as well as the TM/DPMS pair I have though, which is disappointing. It is not a bad fit, but there is a little play. All parts have gone in fine so far.
As this page is not yet as comprehensive enough for me, I advise you to check out www.308ar.com. I found a lot of good information from that site and it was one of the many sites that gave me the inspiration to make this one. The guy does his research and put a lot of effort into the site.