ok, so I've been reading quite a bit about this subject and I am torn over whether or not to lap the Burris PEPR one piece that I just got. I am putting a Leupold Mark AR 4-12 x 40mm on it and the scope seems to sit very well in the rings with no bind what-so-ever (nice and clean). The thing that is bothering me is when I press down on the scope in middle and towards the rear ring, i get no movement, however, when i move the pressure past the middle point towards the front ring, i get just a little scope movement (kind of like a small high point on the back of the front ring) making it teeter up and down.

i'm pretty comfortable lapping it with a wooden dowel and 600 grit paper (ive read where lapping bars and compound don't work real well on aluminum rings) but my biggest problem is whether or not removing the anodized coating on the aluminum is going to cause me any long term problems between scope and rings?

any input would be greatly appreciated.

No it will not cause a problem. I do however suggest the proper tool for the job and some gauges. A dowel rod and sandpaper is NOT the way to go.

thanks for the input on the anodized coating.

From what i have read, the way lapping compounds work, is that the compound embeds itself in the softer material (the lapping bar) when lapping steel rings and wears down the rings. when attempting to lap aluminum rings, the compound will embed itself in the aluminum and wear more of the steel lap bar than it will the rings. The way most (from what I have read) get around this is to use a 1" dowel with emory cloth wrapped in a single layer and gently work the aluminum. Mechanical reaming is the other alternative, but I am not set up to do that.

I am certainly not an expert but I have done at least 20 of my own and 30 or so friends with excellent results. Be careful whatever method you use. 80% contact is sufficient and anything more is dangerous. Problem with the paper is it rolls up a bit and can wear down the edge of the ring which is a bad thing. You can't see it but it does.

much appreciated. were all of these that you have done steel ring sets or aluminum? i have lapped steel rings before, but not aluminum. like I said, i have good contact, but the little teeter on the front ring make me think i have a small ridge. it's almost imperceptable and I can't "feel" it with my finger, but it's there or the scope would move at all.

Gentlemen,
What does "lapping" mean, and what is it done for?

Lapping is the process of rubbing two pieces of metal (or other materials) together with an abrasive compound applied in order to make both surfaces "mate" (or resemble each other) and have as much of both of their surfaces areas touch as much as possible. Specifically with scope rings and scopes, if the ring surfaces aren't "trued" to the roundness of the scope tube, it can result in pinches, warps, and misalignment of the scope causing it to forever need adjustment.

It's never happened to me and I have mounted a many of scopes. I suppose I have been lucky......

Honestly, on my guns, there are no aluminum rings. Lapping aluminum needs to be done with different compunds and bars than steel, if you must. But seriously consider better rings.

In this case it is light grinding/polishing the rings to true them so that they both are perfectly aligned and mate better with the scope. In my case it is my old suburban that could use a valve job if not a full rebuild...

ww

I have done both with the same tools. Honestly, you will be hard pressed a serious bench rest or long range shooter that doesn't have his optics lapped in.