Scope mounts and lapping..??

Discussion in 'Videos Of Tech Stuff And Reviews' started by Sully2, Mar 11, 2011.

  1. Sully2

    Sully2 Well-Known Member

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    Seems like the latest thing in rifle scopes is to lap the scope rings with a lapping bar and very fine grinding compound. Do you do that?? Or is it a lot of hooie and "BS".??

    I have the mounts and rings installed on my new varminter but placing the scope body itself down into the bottom half of the ring(s) it doesnt just "drop in" like I thought it might...but instead its a very snug fit. I might not have the front ring just exactly square with the rifle bore and that could cause a "sideways" pinch to make the fit feel snug....I'll just have to check and double check that. Of course a lapping job would take most or all of that away...making the bore of the rings a perfect "cylinder".

    Do you or have you lapped in a set of scope rings??
     
  2. SBruce

    SBruce Well-Known Member

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    Yes, many times. It's not so much a new thing as it is more people are maybe paying attention to it now.

    I've been mounting alot of high dollar scopes lately, and don't want ring marks if I can avoid it. I also don't want to take any chance of bending the tube on those expensive scopes. Additionally, lapping in properly gives more surface contact between each ring and the scope, thereby theoretically adding more clamping force, and less chance of scope slippage inside the rings.

    Lapping is not a cure all however, some rings are "pinched" and need to be slightly spread out or they will mark the scope. Others are not aligned with one another exactly square left to right (dovetail and windage adjustable types are kinda famous for this). A precision made scope ring alignment tool will show you if this is the case, and a lapping bar will aid in alignment of those types of rings. Still, another issue that crops up sometimes is that one ring is higher than the other, which is where shimming comes in. I haven't done any of that, and hope I never have to.

    Sinclair/Brownells make scope alignment and lapping kits, so does Wheeler. I prefer the lapping compound that comes with the Sinclair model, it seems to clean up easier.
     

  3. Buano

    Buano Well-Known Member

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    I concur with everything in the last post & add that I recently started lapping rings. I was amazed how far from "perfect" rings were that seemed "dead on".

    With $100 scopes lapping is an option, but when scopes started costing me well north of $1,000, it's worth the time & effort to get the rings "right".
     
  4. marchboom

    marchboom Member

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    Look into Burris Signature rings. Never lap again, no ring marks, great clamping power, ability to adjust scope within the rings.
     
    Last edited: Mar 28, 2011
  5. Buano

    Buano Well-Known Member

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    I concur, Burris Signature rings are great & don't require lapping due to the plastic insert. The only problem (besides cost) is they aren't made for every application. In fact, the last 3 guns I mounted scopes on did not have Burris Signature rings available to fit!
     
  6. ken snyder

    ken snyder Well-Known Member

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    Burris signature (PERIOD). They go up down and all around. The average action isn't straight or in plain, its almost a wonder that scopes have enough adjustment to compensate. A set of .005 bushings will take care of most concerns. Set your scope to optical zero and twist the rings until you are zeroed, then enjoy 100% scope adjustability in all directions. P.S. no binding or kinking either
     
  7. ltrshooter

    ltrshooter Active Member

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    I have started at least checking all of my rings with an alignment bar. All of them needed lapping with the excepton of Ken Farrel rings on their picatinny rail. On one piece bases, once again only the Ken Farrell base fit without bedding. It hurts me to watch the uneven one piece bases pulled down with the screws. I cannot imagine it is good for the receiver.
    I find it is imperative to use locktight also. The 6-48 screws so commonly used are very small with very little torque to hold them in and they seem to come loose, particularly on my 338-06. Someday, I would love to tap all my receivers for bigger screws.. I notice the high end guys are using 8-40's now. I am afraid of tapping my own without a fixture. If you think of how little the erector moves inside the scope to change point of impact, I am a believer in high quality rings and bases now with bigger screws, locktight, and some bases have recoil lugs, additionally, bedding the bases and aligning and lapping the rings.
     
  8. ken snyder

    ken snyder Well-Known Member

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    Bigger screws are cool, after you strip out the little ones, or you are getting a custom mount. Truth is most rifles and mounts don't need any help. I can't think of a quicker way to ruin a set of rings than lapping them improperly. It's kind of funny that people will spend $1,500 on a scope and then cheapskate out of having a gunsmith set it up for them. Sometimes things really are out of alignment and a lapping bar is not going to help.
     
  9. philip140

    philip140 Active Member

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  10. ken snyder

    ken snyder Well-Known Member

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    The only reason a scope will slip in the rings is because the ring diameter is the same or larger than the scope tube diameter. If the scope is used and with its release agent it will be slightly larger than the tube diameter. This produces a bushing bearing, great for a motor with a spinning shaft. The friction that holds a scope in position is a product of pressure not of surface area. When economy is at stake use an old scope that is slightly smaller or a machined tube that is slightly smaller than your intended scopes tube diameter for bedding. Even then there is a lot more to it than simply throwing some JB weld on it. I never have seen something actually get fixed by screwing it up! Compound the friction and use less torque!
     
  11. philip140

    philip140 Active Member

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    I'm not sure I agree with your theories, but an interesting point none the less.
    Using the bedding technique has always worked for me, using rings without 100% contact has not unfortunately. There are several reasons for bedding a scope in the rings, not just to reduce the chance of a scope shifting under recoil, but also to prevent rings marks (from pinching), to prevent the action transferring stress to the scope and vice versa and also to enable you to remove the scope and re-attach without loss of zero.


    Phil
     
  12. Gary Kaney

    Gary Kaney Well-Known Member

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    10/4 on the Burris Rings. I've only got onr rifle left with lapped rings.
     
  13. philip140

    philip140 Active Member

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    The thing I really like about the burris rings is the insert kit you can buy that'll give you more elevation without the need for using a canted base. You can even shim the rear base (if you have 2 piece bases) for more elevation without warping the scope like regular rings will.

    Phil
     
  14. Clark

    Clark Well-Known Member

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    If I buy a rifle with rings that were lapped, I take the rings off and throw them away.
    I have a lot of rifles and a lot of scopes. They play musical chairs with mounts staying with rifles and rings staying with scopes.
    I glass bed between the mount(s) and receiver.
    I align the mount(s) during bedding with fixturing so that the mounts are co planar, co linear, and a scope with the reticule adjusted to the center of the tube will be bore sighted or 20 moa high.
    So I do not get ring marks and when I put a scope on a rifle, it is on the paper.