The newer ringmounts, with the torx screws (which are same head size as the action screws), are spec'd to be torqued 45-in/lb. The action screws are spec'd to be torqued 55-57-in/lb. I have found my action screws hold torque and stay put when set same as the ringmounts at 45-in/lb. I take my scope off fairly often for travel and to use the fixed sights. Keeping things simple, I picked up a compact Felo torque screwdriver which I use to remove the ringmounts, remove the action, reassemble and re-torque. Doing so, the rifle has proven repeatable shooting back into the same groups. Not sure if this is your issue, vs something broken, but it is something to consider.
In additon to the above, I tend to keep a proven test lot of ammo along with a target if things appear askew down the road. I then can come back and bench the rifle with the test ammo to compare groupings. This eliminates some of the guess work.
Good Luck
