Do you always lap your scope rings?

[teesquare]

And the point that the rail and action may be off. Perfect rings on an action that isn't true is still an issue.

You make a good added point....we have talked about receiver screw holes being mis-aligned, and the receiver not being sure to the barrel...but I suppose you could have a pic or weaver rail that was not drilled true to the action as well.....

 

[Gone Ballistic]

Re: Bearing housing; does it have to be concentric & coaxial with other bearing housings, or does it just need to be round? And how round is round enough?
If it needs to align with others, and it/they are not, and/or it is not round enough (to size) then I'm going to hone or lap it inline with all of the others at the same time. If it/they are aligned well enough and are round enough for the purpose then move on to the next item that needs to be addressed. Why do work that gains you nothing?
It is certainly possible to lap rings too much and end up with rings that are over-size that will never grip a scope tube securely enough. When that is a possibility with no easy method to recover from it then the grit choice should err on being too fine. A too coarse grit just means that you can go over-size much faster than you thought.

In the case of the rings that I had to lap there were no separate bases to first true. In the case of the base that I lapped, it was pretty clear, before even getting as far as installing & checking ring alignment, that the base needed some work to fit to the action correctly.

You said that well. First off, if you are going to lap rings correctly you must be extremely careful as you remove the material that is causing the misalignment of your scope. I try for a minimum of 90% contact of the scope by the rings. This will insure that I have zero movement from the scope. I go with a jeweler's polish to make sure that the rings are excessively smooth before I tighten them down on the scope. You can use a large black marker to coat the inside of the ring each time before removing more material as an indicator of what is still needed to be removed in materials. Just remember to go slowly and keep checking. I always use a fine to extra fine polish to make it as perfect as possible.

 

[highdrum]

I'd lap with a fine grit compound, an additional step is to bed the rings to your scope as well!

 

[shinbone]

To each his own, and here's my two cents:

Unless using the Burris plastic inserts, I always lap my scope rings. It is a quick and easy process with no downside. Plus, a lapping bar does not lie about alignment, and I have never ever seen rings that were perfectly aligned, no matter how expensive they were. The better rings take less lapping, for sure, but they still benefit from lapping.

Whether such perfect alignment is needed, is another question. But it does not hurt when done properly. No way am I clamping a $1000+ precision optic without 100% confirmation the clamping surfaces are concentric and co-linear and free from pinch points and surface defects. Even if the benefits are only aesthetic in not marring the scope tube, it is well worth the minor effort.

JMHO

 

[johnnyk]

Do you always lap your scope rings? How about on shorter range only setups (under 300 yards)? What lapping tools do you use?

Never have.