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Scope Shimming

Discussion in 'Gear & Accessories' started by sandman1212, Apr 1, 2012.

  1. sandman1212

    sandman1212 NW Oregon Active Member

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    I have an AR at I can't seem to get scope reticles to go low enough on. I have had a recommendation to shim the scope. Has anyone done this, and if so how did it work? what is the best material to use for this? Copper, aluminum etc.?
    I have seen shim sets on Brownells and other sites for 10 bucks or so, but I have small metal around that I can use. is there an advantage to using a manufactured one?
  2. 2gr8dgs

    2gr8dgs oregon Active Member

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    I have used leafs of a feeler gauge, & a strip off an aluminium can, folded to the right thickness, under the front or rear ring. It's trial & error. they worked just fine, but I could never get comfortable with toting around a shimmed up (rigged) scope.
  3. SquackDaddy

    SquackDaddy Marion County Member

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    I personally don't feel shimming is the way to go when you can purchase scope mount with a built-in 10 or 20 MOA elof negative elevation. I also believe if you use Burris Signature Zee rings, you can get scope inserts that could give you the elevation adjustment you need without resorting to shimming. (which is an inexact undertaking that may result in a less than optimum contact between the scope mount and the receiver......which can make accuracy suffer, not to mention possibly putting stress on the scope)

    mjbskwim and (deleted member) like this.
  4. mjbskwim

    mjbskwim Salmon,Idaho Well-Known Member

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    +1 on the 20moa bases.Pretty common on long range rifles and probably way better contact than a shim.
    Plus you are putting unusual pressure on the scope when you shim one end and have the other end at an angle in the ring. May not be much,but may tweak the scope enough to change accuracy
    SquackDaddy and (deleted member) like this.
  5. pioneer461

    pioneer461 Columbia County, Oregon Active Member

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    I am a former employee of Leupold. Their tech service folks recommend shimming and (at least when I worked there) they will send you some if you ask nicely. I've never found a need to shim any of mine, but I know of many alignment problems that have been corrected by doing that.