Scope Ring Lapping

saleen322

New member
I picked up a Sinclair ring lapping tool at a gun show. There were no instructions with it. I would appreciate anyone's advice on how the process should be done as this is new to me. Thanks in advance.
 
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Also needed

Might need an alignment indicator to tell when you are straight. here is one from Brownells: http://www.brownells.com/.aspx/pid=833/Product/SCOPE_ALIGNMENT_RODS Did you get lapping compound with the tool? The basic operation is fairly simple. Use the bar/lapping compound to remove metal from the rings until things line up. Typicaly about 70%+ of the internal surface of the rings show material removed. Start with the lower rings only. You can add the tops later, but most of the work is done on the more solid lower part.
 
I picked up a Sinclair ring lapping tool at a gun show. There were no instructions with it. I would appreciate anyone's advice on how the process should be done as this is new to me. Thanks in advance.

For instance... Leupold turn in rings - line them up as close as you can.

With the tops removed run the lapping bar in them... it will probably feel tight and bind a bit. Adjust the front turn in ring if you can see that is required. Often the rear ring sits turned a bit die to the windage screws... I will lay the lapping bar in both rings and with the windage screws loose push down hard and while holding it there tighten the windage screws. The usually gets the rear rings as square as you will get it.

Then I put a little oil on the lapping bar and the rings bottoms and some 120 grit abrasive and twist and move the bar in short stokes... it quickly becomes easier to do and I stop and see where it is removing edges and bluing. Hopefully it is fairly even and soon the bottoms become pretty true to one another.

I then clean well and add powdered rosin to the ring bottoms and tops and install the scope.

Ring tops do not require lapping. They align with the scope tube when the screws are tightened, and the scope tube aligns with the bottom halves.
 
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In Defense

In defense of the Brownells alignment kit that I use, The pointy bars are just the start. One of the bars is longer and, per the instructions, is designed to slide from one set of alignment rings into the other. When it glides smoothly, you are stress free. The only time I use the pointed indicators is to show someone how far off their rings are before starting the lapping process. By the way the current record is an aftermarket set of xhigh rings that popped the front lens out of a Burris tactical on a Ruger.
 
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