Results 1 to 5 of 5

Thread: 30mm ring alignment rods /ring lapping

  1. #1

    Default 30mm ring alignment rods /ring lapping

    A new model high quality German scope is on the way to me. They want it tested out in Alaska, on a magnum rifle, and for ATV / snowmachine shock on the trail. Anyone got 30mm alignment rods and willing to give me a quick hand aligning the rings (I'll drive)?
    What can anyone tell me about lapping the rings? Helps? unnecessary? non-sense?
    Thanks.

  2. #2

    Default Check out the Article in the latest American Rifleman

    There is a well written article in the latest American Rifleman magazine about scope mounting practices. The author suggests that more harm than good is usually done by lapping scope rings. The alignment rods, however, are a very good tool. If the rings don't line up nearly perfectly in the vertical plane, shimming is the best approach. If they are misaligned in the horizontal plane, lapping may be the only solution, but it needs to be done with a lot of skill and care to prevent causing more harm than good. Lapping removes the smooth surface on the inside of the rings, leaving "sharp" edges that will mark up the scope's tube. It also makes the rings i.d. larger, so the clamping force applied to hold the scope becomes concentrated in a smaller area on the scope tube, in the plane parallel with the clamping force.

    Check out the AR article. It has diagrams and good info.

    Jim

  3. #3
    Member danattherock's Avatar
    Join Date
    Apr 2006
    Location
    NC
    Posts
    5,608

    Default

    Lapping rings makes them more concentric and removes imperfections from the manufacturing process. Both lend themselves to increased accuracy. The 220 grit lapping compound does not leave "sharp edges" inside the scope rings. Nothing could be further from the truth in my experience. Smooth as a baby's butt. Did it on a 300 Weatherby and Armalite 50 BMG. Both rifles hold their zero and perform flawlessly (sub MOA). It is easy to do but should not be done heavy handed. While easy to do, it is a deliberate process and one of those cases where more is not neccesarily better. Instructions come with the kit, but I will be happy to walk you through it if needed. It can be done properly in half an hour. PM me if applicable. Below is the kit I got. Best $40 I ever spent.

    http://www.midwayusa.com/eproductpag...eitemid=879712
    The two loudest sounds known to man: a gun that goes bang when it is supposed to go click and a gun that goes click when it is supposed to go bang.

  4. #4

    Default More Thoughts on Ring Lapping

    Dan said: "Lapping rings makes them more concentric and removes imperfections from the manufacturing process. Both lend themselves to increased accuracy. The 220 grit lapping compound does not leave "sharp edges" inside the scope rings."

    This is 100% correct in the context of Dan's note. I have lapped rings myself, with the desired result. I would just suggest that you run your fingers across 220 grit sandpaper if you believe that it is not leaving sharp edges at all. Of course, under enough magnification, the surface of steel polished with 1600 grit looks like a jagged mountain range. The requirement is "smooth enough" so it won't leave marks on the scope tube, and 220 grit will work for that. I personally finished the job with 600 grit compound, and it made me feel better about it, even though it may not have been necessary.

    One thing to be aware of if you determine that lapping is needed: the edges where the ring split line meets the cylindrical surface will be "sharpened" by lapping. The edges are generally smooth and slightly rounded during the final polishing process from the manufacturers. The lapping process will remove some material from the cylindrical side, which can lead to edge that has the potential to mar the scope.

    Dan is also correct in saying that lapping shouldn't be done with a heavy hand. Most manufacturers' products have minimal to no defects to remove, for all practical purposes. It is more common for the rifle's mounting screw holes to be slightly misaligned. If the mis-alignment is in the horizontal plane (one mounting surface higher than the other), shimming is a better approach than lapping. If the misalignment is in the vertical plane, lapping is the only alternative that will produce true concentricity and parallelism.

    My experience has been that high quality rings and bases will generally not be improved by lapping. There are exceptions, but I would be more inclined to exchange them for a non-defective set than trying to repair them.

    If the misalignment is slight, lapping done properly and carefully will accomplish just what Dan said, and give you great results.

    Good Shooting!

    Jim

  5. #5
    Member danattherock's Avatar
    Join Date
    Apr 2006
    Location
    NC
    Posts
    5,608

    Default

    Jim makes a good point about using high quality rings. Lapping is not a cure for cheap hardware. I would be willing to bet that some of the info in the article mentioned stemmed from people doing just that. And perhaps over doing the lapping process as well. In such cases, no doubt you will have problems. Buy the best rings you can find. In doing so, you should have very little material removed in the lapping process. But in the two times I have lapped rings, 40-60 % of the interior surface of the ring was reduced in order to achieve 100% concentricity. This is largely what I meant by not being "heavy handed". And I used the best rings I could find. Only taking off what is needed, and no more. Always buy the best rings you can afford.
    The two loudest sounds known to man: a gun that goes bang when it is supposed to go click and a gun that goes click when it is supposed to go bang.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •