tight groups with several different brands and weights of ammo. It liked CoreLokt 180 grain ammo best
Did you use one of these at the same wieght ?
If you removed the barrel and action from a non-free floating stock . You most certainly could have changed presure points on the barrel.
If the screws were torqued to a different specs then the last time . That could cause problems .
Any of these things can cause your rifle to lose zero . Put them all together and it can get out of control fast .
This is nothing that was not said earlier . Im just not sure if you answered and or commented on the questions/statements