Bridging the Upper Receiver Rail and the Handguard Rail on an AR?
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Thread: Bridging the Upper Receiver Rail and the Handguard Rail on an AR?

  1. #1
    XCR Guru Sean K.'s Avatar
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    Bridging the Upper Receiver Rail and the Handguard Rail on an AR?

    Being told by BCM it is a no-no to bridge the upper and handguard with a scope mount or rings.

    Here's the email: "You are correct, never bridge the two rails in any way, including using ring mounts split between the upper and the handguard. "

    Why?
    "Necessity is the plea for every infringement of human liberty. It is the argument of tyrants; the creed of slaves."-William Pitt the Younger

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    Marksman scalton's Avatar
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    Quote Originally Posted by Sean K. View Post
    Being told by BCM it is a no-no to bridge the upper and handguard with a scope mount or rings.

    Here's the email: "You are correct, never bridge the two rails in any way, including using ring mounts split between the upper and the handguard. "

    Why?
    my guess would be flexing between the two but I am not sure
    Walking through the waste land formally known as the USA

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    XCR Guru Sean K.'s Avatar
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    Quote Originally Posted by scalton View Post
    my guess would be flexing between the two but I am not sure
    So are they right or is this just someone's opinion?
    "Necessity is the plea for every infringement of human liberty. It is the argument of tyrants; the creed of slaves."-William Pitt the Younger

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    XCR Guru Bravo's Avatar
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    My GUESS is that it's legit. After all, if it wasn't legit, why would monolithic uppers be desirable to the point of paying the extra dough?

    But it's ONLY a guess.
    Do you really think we want laws to be observed? We want them broken. There's no way to rule innocent men. The only power any government has is the power to crack down on criminals. When there aren't enough criminals, one makes them. One declares so many things to be crimes that it becomes impossible for men to live without breaking laws. Who wants law-abiding citizens? Pass the kind of laws that can’t be observed, enforced, or objectively interpreted - and you create a nation of law-breakers.

  6. #5
    Marksman scalton's Avatar
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    Quote Originally Posted by Sean K. View Post
    So are they right or is this just someone's opinion?
    I'm not sure but it makes sense it does give it one more point to move
    Walking through the waste land formally known as the USA

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    XCR Guru Sean K.'s Avatar
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    Thanks guys....guess I'll be looking at a new mount.
    "Necessity is the plea for every infringement of human liberty. It is the argument of tyrants; the creed of slaves."-William Pitt the Younger

  8. #7
    XCR Guru WatchoutforStobor's Avatar
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    I've got a Vortex scope on order and I am looking at the Larue LT104 mount. It is a cantilever mount like the Burris peper mount, and others. The point of the cantilever is so the base is connected only to the upper and not the rail. I will assume this will give the best accuracy and consistency.

    The question is how much accuracy do you need? If you are going for minute of pie pan I think you would be just fine.

    Just my two cents worth.
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  9. #8
    XCR Guru mjorin's Avatar
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    Then rail mounted BUIS's are inaccurate? Another plus for the XCR!
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  10. #9
    XCR Guru fmunk's Avatar
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    Like the others have said, flex with the handguard will throw your zero off, especially with the light weight ones that are all the rage now. Plus, I'd imagine heat transfer from shooting and the different materials (steel & AL) involved will also have an impact on retaining zero.
    Fool-proofing serves only one purpose: identify bigger fools.

  11. #10
    XCR Guru Sean K.'s Avatar
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    Ya, I'm going to have to either get a cantilever mount or go with separate rings; not a one piece base. If I try to go really low, then I'll go separate rings with the XS 45º sights. If I go with traditional BUIS, then I'll go with the taller LaRue SPR-S LT158.
    "Necessity is the plea for every infringement of human liberty. It is the argument of tyrants; the creed of slaves."-William Pitt the Younger

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