Shim up the rear base. Any decent gunsmith will have the shims and using a bore scope can get you centered without touching your turrets.
Borescopes are used to inspect the interior of the bore. And to lower the POI, you would need to lift the front end of the scope.
Unless the scope base is 1 piece, you run a risk of damaging the scope by shimming one end. If you cannot solve the problem with the gun, then at best you should look at the Burris Signature Rings with the offset inserts. These are designed to place the scope off axis without the potential of bending the tube. But before I did anything, I would do a little more investigating to see why the bore and the receiver are so out of whack. And if it's a manufacturing defect, make Kimber correct it, at their expense.
