This is kinda my next rifle... after my goat hunt... really left me wanting/needing something lightweight and accurate to in my eyes 600-700yds would be awesome.
I think a custom ultralight build I'd lean towards the 6.5prc in a short action..., since I don't reload and am looking for the most bang for the buck in a factory rifle with the traits I want, the 7mm PRC really looks promising.
It'll shoot a bigger higher bc bullet than the 6.5 at supposedly 175@ 3000fps vs 143@ 2900.
From what I've been looking at you're really not saving weight in the 6.5prc but in a custom rifle I think you could design it and save a little bit extra, also many factory 7mm PRC have 22" barrels which I want, vs the 6.5 seems to get the 24" more often than something shorter, although I think I've seen a couple 22 and 20" options out there.
also with a brake on the 7mm PRC I don't think I'll be worried about kick etc... and in the field I could have or not have the brake...
Also I think as a 1 do all gun the 7mm will let me hunt elk and moose more effectively than the 6.5 although it can probably also do both within reasonable ranges.
my short list is, bergara, fierce, savage, at the moment...
good luck, keep us posted, what you're thinking/ get...