I bought a Leopold STD 2 pc base set and Leupold rings with the front extended ring. W/O this extension turned backwards, I'd not be able to get the scope far enough back for a proper check weld. I am using an analog Bushnell boresighter to sight in before range tests. I always set the scope's adjustments to mid-scale prior to mounting. Windage is easily adjusted with the rear screws. Problem is I have run out of vertical adjustment with the POI shooting too low. I cut two shims from a soda can and laid them in the bottom of the back ring. It has brought my POI up adequately. BUT......Is this a wise practice to do this and put pressure on the scope's tube? I am looking to fix this in a better fashion. My thoughts for options: *Replace rings. Does Burris make an insert capable ring that is extended that will work with Leupold bases? This would be an easy fix if this configuration is possible. *Remove some material off the front base. I don't have any professional milling machines, just a Dremel tool with assorted grinding stones and polishers. Material removal is sort of a "guess" w/o better equipment. *Put a shim under the rear base. I have never done this so I am not sure how to go about it. *Take to gunsmith and have it done professionally. Probably be at least $80, maybe more. Thanks for suggestions!!!