Are you acheiving groups with the loads or are they spraying all over the place? (what type of groups are you getting??)

When in the rest is the barrel free, meaning no downward pressure from rest or shooter?

Have you enlisted another shooter to see how it fairs with someone else?

When I have accuracy problems I do a check list - condensed version:

#1 baseline load check if not brand new(a load thatis proven in the rifle for accuracy)
#2check ring/bases for damage and loosened screws
#3 check action screws and possible bedding issues
#4 shooter (technique, rest, etc)
#5 replace scope with a proven scope