I just finished rescoping an old tang safety Ruger in 25-06. The rear base was visibly offset to one side of the rifle.
I used the Burris Signature Zee rings and ordered the set of offset inserts. The set contains three poly inserts of .020", .010" and .005" offset. I set the front end of the scope 20 thousandth's to the right and the rear of the scope ten thousandth's to the left. If my math has not failed me, that gives 24 moa correction with the scope rings spaced 4.5 inches apart.
That put my first group less than four moa off of the bull with the scope's cross hairs centered.
It sounds to me like the perfect answer to the OP.
I used to use only Burris/Redfield/Leupold windage adjustable one piece bases with the appropriate rings. That allowed me to switch scopes at leisure between several rifles.
Then I discovered that after removing and replacing the front dovetail a few times, it became very sloppy in the base. I restored the accuracy on a couple of rifles simply by replacing a worn out dove tail ring and base set.
I absolutely love the Burris Extreme Tactical bases as they offer multiple slots for latitude in ring placement, and I use the Burris Signature Zee rings with them.
