Consider the following:
this scope has very little internal travel and if the base/rings are "pointing" a bit down, you will have a high SR zero.
DO NOT shim in the rings, you will crush the scope tube and really not change anything... except maybe, damaging the scope
DO NOT shim under a single base unless you shim on a taper over both bases. If you raise one base and the rings are no longer in alignment, you will crush the scope tube, bend the tube or stress out the internals.
If you need to shim the scope, Burris Sig ZEE rings are the best and only solution that will work with a 2pc base.
But given that you are within a couple of inches of ideal... does it really matter?
Jerry