scope mount thumb screw

Discussion in 'M1A Series' started by markus001, Dec 29, 2015.

?

does anybody know the thread pitch on the M1A receiver scope mount thumb screw hole ?

Poll closed Jan 5, 2016.
  1. 12-28, ??

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  2. 10-32

    0 vote(s)
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  1. Dec 29, 2015 #1
    markus001

    markus001 XDTalk Newbie

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    I need tofind a replacement thumb screw for my scope mount
    does anyone happen to know the screw size and pitch, would
    it be 12-28 ?
     
  2. Dec 29, 2015 #2
    Spawnz

    Spawnz XDTalk 2K Member Founding Member

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    I don't have a clue on the size. I will assume the mount has more than one thumb screw. Take the other to Home Depot and they have a few boards with different size nuts and bolts where you can find what you need. Try to screw it into the different bolts and you can find the size that way.

    That's all I got..................
     
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  3. Dec 29, 2015 #3
    markus001

    markus001 XDTalk Newbie

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    you know what, I did exactly that.....their board went from 10-32, 12-28, 1/4-24, now
    this is on the receiver, a 10-32 was too sloppy, and 1/4-24 to large, and H.D, didnt
    have a single 12-28........................
     
  4. Jan 4, 2016 #4
    ChileRelleno

    ChileRelleno XDTalk 2K Member

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    12/32 unef
    You will not find it at any hardware store.
    You'll need to find a proper replacement.

    Prices, Scope Mounts, Spring Guides,Pistons, Sadlak Industries
    Part # 140010-3P
    Hex Screw, #12-32 UNEF, Steel, Parkerized
    $17.50 ea

    May I ask, which scope mount are you using, SAI?
    Since we don't know for sure what scope mount you'd be using the bolt with (though it sounds like it might be the SAI), you should keep in mind that different mounts use different length screws. If you use one that's too long, it will extend into the channel the left bolt lug rides in, which is not good. Washers under the bolt head will fix that. If the replacement bolt is too short, fixing that will be harder.
     
    Last edited: Jan 4, 2016
  5. Jan 4, 2016 #5
    markus001

    markus001 XDTalk Newbie

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    to tell you the truth, I have no clue what the scope mount model number
    is, it;s aluminum and stamped Springfield armory Geneseo Illinois,
    12-32, thank you, I was thinking it was a 12-28 as sloppy as a 10-32
    fit...and thanks for the length advise
    it came to me from my older brother, the scope on the mount says
    Springfield armory also, government model 4x14x56 pat.D366173 Japan.
    it has an internal bubble level and distance and elevation markings on the
    reticle, I assume thier specific to the 7.62, because for example, a 5.56 has
    a different trajectory than a 7.62 ....is the scope any good ?
     
  6. Jan 5, 2016 #6
    ChileRelleno

    ChileRelleno XDTalk 2K Member

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    The SAI mount is mediocre at best, it has a poor rep. The scope should be OK.
    You can get the proper bolt from Springfield Armory, which would be advisable.

    Most people end up buying a Basset, Sadlak, VLTOR or other.
    The Basset & Sadlak are the probably the best, I use a Basset, low mount.

    For a great wealth of knowledge and friendly people, who revere the M14/M1A, join m14forum.com.
     

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