Re: First AR 10 build
If you are going for distance, i.e. 1000 yds. or greater, then choose something other than .308 as it does not compare ballistically against any of the following: .260, 6.5x47, 6XC, .243 Super, or 6.5 Creedmoor. If your goal is to feed from the magazine, the shorter cases (other than .260 or .243 Super) give some additional latitude with bullet seating to a limited degree. Pay attention to all the little details with the larger brother since all the little things matter that likely don't affect the AR15 like polishing the bolt face and shimming the extension. Zediker's books give plenty of detail as well as many of the posts in the gunsmith section of this forum. Decide on whether you want an actual AR10 (Armalite) or just a large platform (though the MA 10 will work with either parts set)and get the best parts you can. Much is made here about barrels and triggers, but the reality is that these are the most subjective parts of all, buy quality and don't look back as they will all give respectable results, i.e Kriger, Rock, etc... Geissele, X-treme respectively. FWIW I built a full custom DPMS based large platform in .260 with a Krieger tube and Xtreme tirgger fitted by Derek at Accuracy Speaks and it has been consistently sub minute to 1000 yards.