I did search for the answer to this question, but I did not see much of a response. I am looking into building a 308 AR. I have been looking at those Rainier barrels. I probably would get a 16 inch black middy. Does anyone have any experience with Rainier 308 barrels? It seems pretty solid. I wish it was chrome lined though. The only 16 inch chrome lined barrels I see for same are DPMS in the light weight profile. I wanted something with more rigidity and I don’t mind the weight. Let me know if there are better options.
Also, what is a good BCG I could get for it? Is the DPMS BCG just fine?
I will be using Mega Maten receivers for this build.
I just completed a 308 AR build. It was on an SI Defense billet upper/lower set. You will want to choose early on whether you want to run an Armalite or DPMS pattern barrel/bolt, apparently the MATEN receiver set is compatible with either. I would choose DPMS as the aftermarket support is larger.
For a BCG - a DPMS one would be fine. I ended up running a JP Enhanced bolt as it was 1) all I could get my hands on, and 2) arguably better material than the DPMS. I am using a basic DPMS carrier though. JP makes complete carriers, as does SI Defense.
For barrels - I have a Criterion barrel, from Fulton Armory. It is a 20" heavy profile SS with 1/12 twist. If you are looking for a heavier profile for long-range work, this is a good choice. They also stock a 16" and 18.5" barrels, that are available chrome-lined and in a variety of profiles. However, they are pricey @ $350+ for the chrome-lined barrels. As for mine, I only have 25 rounds down the pipe and it shoots quite well thus far. Even with some random thrown together reloads and open sights (optics are pending) it still cranks out 1.5-2 MOA groups.
If I were you, I would choose the 18.5" barrel. In a good medium light profile, it is really not much heavier or unwieldy than a 16" with less recoil and muzzle blast. I believe it is optimal for a 308 AR unless you are using it primarily for long range shooting like I am.
I have no experience with the Rainier Arms barrel, apparently they are made by Black Hole Weaponry.
I am in the process of a 308 build as well. I went back and forth on barrels and was looking at the Rainier select and Black Hole Weaponry ones. I wanted a 1 in 10 twist and came across Bison Armory. I ended up going with their 18" 308 barrel which is an SPR contour as well. Barell should be here in a few days so I can get a better look at it then.
just emailed rainer arms asking about a relationship between their select polygonal 308 barrels and black hole weaponry. i also asked about the black oxide-military hot bath finish/treatment as found on the select barrels… as i know nothing about it. i will share the response.
I also looked at the bison armory SPR barrel. The profile was good, but it was an ER Shaw blank and mid length gas. Not ideal IMO. For $50-75 more you can get a button-rifled Krieger blank and rifle gas if you choose the Criterion. I am still eager to hear about your results, if it shoots well it would be a great value.
About the BHW and Rainier barrels - they share the exact same specs, so I am curious to hear what Rainier has to say regarding source. Also I know someone else who had one of their barrels and it was quite overgassed. However, I feel that most 308 AR barrels are quite overgassed anyways so I am not sure this is a valid comparison point.
Does Fulton offer an 18 or 16 inch mid length gas system barrel? I ask because the rail I have is an 11 inch. It won’t cover the whole tube. Would you recommend using a rail that doesn’t cover the whole tube?
No I do not think they offer a mid-length option, even the 16 inch barrels are rifle gas. From what I remember at least a 12.6 in rail is necessary to cover a rifle gas tube. What rail are you using?
Could you elaborate on this a bit more? What about rifles like the OBR, SR-25, S&W, Remington, Colt and other manufacturers who are in the .308 AR game. What sort of standardization is there with the AR-10 derivatives?
I would like to build something like a .308 DMR but I would like to get a better idea where to start.
On a rifle legnth setup with an 11" handguard the tube could be exposed from (and this is just going off of pure posted measurements) 1/2 to 1 inch. I would not worry about damage to the gas tube from that little bit being exposed.
but I will update when its shooting.