Quote Originally Posted by Steyr View Post
Still better to have no step or fall off at all? If a material compresses - it will change over time.

No shims needed means no issue in the first place. Shims are a poor solution whether hard or soft.
I only said shims (if used correctly) are a possible solution not an ideal one. Hard shims may make the problem significantly worse espcially if applied incorrectly. Tapered shims could be used but the easy option is soft shims which can deform before applying significant bending moments to the tube.
Adjustable mounts are better, yes I own adjustable mounts for this very reason.
The above solutions cure the symptoms not the fault, as has been stated the barrel and scope rail alignment needs to be checked, if a fault is found and cured the symtoms vanish.