Fox,
The shims go w/ the rings and fit @ the top of the ring between the ring halves to make up for variance in scope tube diameter & insure that the bottom of the rings is flat & mates properly w/ the base.
I can send you a copy of the instructions for installing both base & rings but if you have used Buhler rings that have been previously fitted & properly sized to a scope, getting a proper fit to another brand of scope is going to be a crap shoot & if the shims between the ring halves are missing you might as well forget it & use some other type of ring & base system. If you have new & unused Buhler rings w/ the shims you should be good to go if you have a caliper or mike to adjust the ring fit to the scope tube.
I always got a smile out of Buhler's instruction sheet. At the top & in BOLD letters it says "If All Else Fails Follow These Directions".
Properly installing Buhler rings to a scope & to the base is a bit more complex than simply screwing every thing together.
