I have a JP Enterprises AR in .308, and it shoots ok with factory match, but when I use handholds, it shoots way more accurate, and have tailored my loads so that the brass looks like it has come out of a bolt gun after. In my JP, a great load turned out to be the 110 Hornady Vmax, with 49.0gr of H335/2.760 COAL, CCI primers. I'd be curious to see how that would shoot in the .308 MH that people own?
My MH is in 6.5 Creedmoor, so haven't got around to much loading for it yet, or if I will even go that route, undecided still..