Have you held an AR15 vs AR10, for a couple hours ?
I have both and just don't take the 10 hunting.. it does make it to the range.
Have a couple AR15 lowers & uppers for 223, 300BO, 6x6.8, 6.8SP each can get the job done in my terrain.
As far as barrels go, BHW is where I would start, its on my AR10 (20" 243), very accurate.