Good write up with a lot of groups shot, it will help guys save bullets, TIME and powders. i have never shot 4166 but it is supposed to be identical to Varget.
RL15, IMR4895, Varget , IMR4064 ,CFE223 with 168smk/175 have been giving me .3's in three 308(including an AR10) ,i can't honestly tell what's better and came to the conclusion that 308 with Sierra MK just rock. I also found the CCI BR2 to perform slightly better than the Fed210 in my guns. The 178 ELD-M and ELD-X on the other hand have outperformed the SMK ONLY with Varget.
I don't believe recoil affects accuracy in my testing; when i am shooting ,i usually switch between 3 guns(barrels cooling down) with one being 300WM or 450 Bushmaster AR and it has never affected my groups. What affects me personally is a shoulder/chest workout 24 hour before the range .
Good shooting and thanks for sharing.