JKN

I may be able to find the dimensions around here somewhere but the differences in the breech face and lug dimensions between the final bolt and the ones that wouldn't gauge were substantial. The bolts were all stripped when being checked. As a last ditch effort I tried a sized case that easily fit in the case gauge and while it started to turn it bound up very tight. When I got the FA bolt it gauged perfectly with the gauges I had so there was a big difference in dimensions between the two.

Not NiB coated just plain Nitride. https://www.brownells.com/rifle-parts/bolt-parts/bolt-carrier-parts/bolt-carriers/308ar-bolt-carrier-group-308-win-nitride-mp-sku078102004-105380-202840.aspx?sku=078102004 https://www.acmemachine.com/collections/bolt-carrier-groups/products/toolcraft-ar-308-bcg-nitride-bolt-carrier-group-armalite?variant=12352308674645

I just went through this very process. I ordered a Brownells BCG with the barrel and it was no where close to being able to lock on a GO gauge. They sent me two more BCGs. Exactly same issue. They guessed it must be a bad barrel so they sent me another. Same result. I then ordered a Toolcraft BCG. It was similar in measurement to the Brownells parts and also wouldn't lock. In the end I sent the barrel to Criterion and they matched a Fulton Armory bolt to it for the cost of the bolt and shipping. Great people to deal with. Good luck and let us know what works. John

Thanks for the tip. That trigger actually looks like just what I want for this build.

I agree the trigger and the handguard are still wild cards. For the trigger I was hoping to find a deal on one of the adjustable ones. I think I paid $175 for the HS-NM trigger in my AR-15 but if I don't find a deal that will go up or down $50-100 depending on whether I splurge or settle. Rail I haven't figured out yet. That may also end up +$100 once it's done. Only need a strong tube with a sling mount so maybe I will get lucky. Thanks for the catch on the LPK. Other than that are there any other gotchas? Can't find any info on the Brownells BCG but they have taken good care of me in the past so I was considering taking a chance. Since it is has a Rifle length gas system am I OK with just about any gas block and Rifle Buffer system? Thanks, John

Yes the M110 would be my ideal choice but to get it with a Giessele trigger bumps the sale price to $1825 which is way over my limit. Here is my initial rough guess. Please feel free to comment. Keep in mind this gun will not see much use so I am not going to wear anything out but I do expect it to work. Thanks, John

My preference would be piece by piece unless I can save money by starting from a complete rifle. I have a start on a prospective parts list with a few parts missing or questionable.

Hello everyone, Joined here because I am considering building myself a 308AR and this seems like the place for info. I am a High Power competitor and have experience building, feeding and shooting the AR-15 but have always wanted a "big gun". My goal is a low end build that functions and groups well and is configured so that I can use it for HP (20", Free-Float HG, A1 stock) when I want to. My main concerns are to make sure all the parts are compatible and hopefully avoid any of the parts with well known issues. I agree with the buy once cry once philosophy (it's going to have a $200 trigger in it for sure) but I also have to be careful or I will overspec it to the point where I can't afford it. Any advice on the best way to get feedback from the forum on a complete build would be appreciated. Thanks, John