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This much misalignment of your cheese-grater will cause 20 MOA error...

Discussion in 'Rifle Country' started by W.E.G., Jul 11, 2009.

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  1. W.E.G.

    W.E.G. Member

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    This much misalignment of your cheese-grater will cause 20 MOA error...

    …in point of impact if your front sight is mounted on the cheese-grater.

    5 MOA error for every 1 degree misalignment.

    [​IMG]

    [​IMG]
     
  2. gvnwst

    gvnwst Member

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    Somewhere.........
    This is why I have a monolithic rail. ;) :D
     
  3. jpwilly

    jpwilly Member

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    Yip - It's called a "canted front sight" and it's going to be an issue down range.
     
  4. jhco

    jhco Member

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    Wow thats not good
     
  5. RyanM

    RyanM Member

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    Hm. Yikes. I believe that is why the list of handguards which are consistently suitable for optic mounts (and by extention, front sights) is very short. And I don't recall Troy being on them. KAC (not the RIS), LaRue, Magpul, and Daniels, IIRC. Edit: and Vltor. I knew I was forgetting one.

    It's also fairly obvious that someone at Troy doesn't know how to count. 12, 13, 14, 16. :p
     
    Last edited: Jul 11, 2009
  6. Uncle Mike

    Uncle Mike Member

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    never never land...never land here!
    Loosen it up and index it... it is a common problem... no biggie!

    :D
     
  7. MCMXI

    MCMXI Member

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    I've got a Daniel Defense Omega rail on my POF but I have a Troy front sight mounted to the gas block ... works for me!

    [​IMG]

    :)
     
  8. Eightball

    Eightball Member

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    Wow. Didn't expect to see that much rotation.

    What'd you expect?
     
  9. W.E.G.

    W.E.G. Member

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    Went back to the range today.

    Considerable improvement from yesterday's 40 MOA debacle. [​IMG]

    Despite having resolved the gas-block interference issue, I still could not get the two halves of the Troy rail to cinch-down in perfect relation to the
    upper receiver. The Troy rail is still "cocked" a little to one side. I swear I "bridged" the rails, and Itried everything including voodoo to try to make those
    halves settle at just the perfect spot.
    tighten-loosen-wiggle-shift... tighten-loosen-wiggle-shift... tighten-loosen-wiggle-shift... tighten-loosen-wiggle-shift... tighten-loosen-wiggle-shift... [​IMG]
    No dice.

    [​IMG]

    I ended up having to put one-and-a-half turns right windage on the knob to bring point of impact to center.
    The sight allows just over three full turns left or right from center if needed. So, I can live with this.
    The gun ran 100% with-and-without the suppressor using Federal white box XM-193. So, at least I didn't bugger the gas system. [​IMG]

    [​IMG]

    One “discovery” to note”
    I discovered that this gun shoots about 5 MOA to the left when the suppressor is removed.

    Otherwise, the targets below were each fired with the suppressor.
    None of these results are anything to write home about, but they are what they are.

    Best target at 100 yards today was with the EOTECH while the targets were shade by cloud cover.
    The shot out the bottom here happened when the sun peeked out suddenly for one shot during the string.

    [​IMG]

    Another weird thing I discovered was a shift in point of impact when the gun was allowed to cool for only a minute or two.
    Using the scope, I could shoot pretty decent groups about 2.5” as long as I kept the suppressor consistently hot.
    When it cooled, even for a minute, it would consistently “throw” the first shot when firing resumed. Then the rounds would drop back into the “group.”

    I would really like to be able to speak to the question of where does this gun shoot from a stone-cold bore.
    I do not know the answer to that question at this time.

    The out-of-the group shots (including the off-the-target shot) are circled or marked by magic marker here.

    [​IMG]

    Next purchase will be a FACTORY-INSTALLED front sight on the gas block, and from a major manufacturer.
    The guys who do this all-day-every-day must have it figured out better than me.
     
    Last edited: Jul 12, 2009
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