Put your shim where the bottom of the action contacts the stock.
That will float your barrel with minimal torque on barrel and action.
With your shim job, the shim provides a fucrum, the tight screw is the force.
You are bending the barrel and action.
People make bedding hard, it's very simple.
If possible, you want the part of the action that has the screw holes to contact the
stock evenly and firmly.
The recoil lug should bear firmly at the rear, and snug on sides. Front is contested.
Bottom of lug should not touch. Unless, the screw holes are in the lug, then floating it
will induce stress when the screws are tightened.
