Rainer ultramatch .308 upper on a 5d tactical 80 lower

[Rhymtime]

I'm interested to see if anyone has matched a Rainier Arms Ultramatch .308 billet upper receiver mod 3 on a  5dtactical AR-308 7075-T6 billet 80% lower? I've seen a few different upper combos that work together but don't really match up cosmetically. Any help seeing how they match up would be greatly appreciated.

[98Z5V]

Nobody bit on your intro question, which was the exact same question, so it's a pretty safe bet that nobody here has done this combination. You will be "that one."  Congrats, and get to it, and let us know how it goes.

I can tell you about Rainier Billet UltraMatch uppers in 5.56 - they can't be equalled.  I have two of them, and they're head and shoulders above all other AR15 uppers, for accuracy builds.  They really are better than other stuff out there.  They hold the front receiver threads to 0.0003" square - yes, that's 3/10-thou.  Whoever is making them for them is really getting it done.  It's quality.