First thing I'd do is check the scope. If all the ring & mount screws are tight, try replacing it with another scope that you know is good, not a new unknown, and see what happens.
Next I'd check the bedding, glass bedding if it hadn't been done, and floating the barrel.
Action screws are tight, right? The center screw (if any) is just snug?
Finally, if I'd seen no improvement, I'd get it re-crowned.
It sounds like scope or bedding to me, tho.
Good luck!
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