Scope Mounting Problems

I am mounting a Zeiss 3-12x50 30 mm tube on a Weatherby Vanguard Wilderness, 30-06.

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!!!

I'll agree that shimming the bed of the ring may lead to scope problems. The most straightforward fix is the shim under the rear base so the base could be transferred to another rifle. RJRivero's fix which is something I am strongly considering too.

I have a question about lapping the front base. If I mic the base as is, am I targeting a specific amount of material removal? Would I want to remove 8/1,000 which if I am not mistaken, is the thickness of two strips of soda can material (4/1,000 ea) which is what I have now in the rear ring? If I have a removal goal, this would help me hit the target w/o mounting and remounting the scope just to see if I am close. What is my best approach since I surely don't want to overshoot my mark.

LoonWulf said:

could the rings or mounts themselves be out of spec? I blamed my 700 for messed up mount holes for years before finding out the base i was using were very slightly off.

Click to expand...

I'd say the rings/bases are at fault based on what has happened. I started with Talley integral base rings and ran out of windage adjustment to the right before it got to zero. I was not sure what was out of alignment so I took them off and put on Leupold STD bases and ext rings knowing this rear windage system would take care of horizontal mis-alignments. Lo and behold I ran out of vertical adjustment with these rings. What???

I switched (rotated back to front) the front base around but no change. I realize I could have lapped the front Leo base down, but I opted to shim up the rear under the base. It now zeroes perfectly at mid-scale scope setting, so all I have to do next is take it to the range for some test firing. I am using an old school Bushnell analog bore sighter I have used for years. I made sure my bore arbor was adjusted correctly and even tested it on a 30-06 that I know the zero is right...it was dead on.

This all leads me to think that both scope bases are somewhat misaligned. The Talley was off horizontally and the Leo was off vertically. I am scratching my head over this one even though I think my problem may be solved with the rear shims. Has manufacturing technology precision gone to the dogs? I have mounted many dozens of scopes in my time, and this one threw me a curve ball.