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AR 10 build problem

Discussion in 'Build it Yourself' started by greeniron, Aug 10, 2019.

  1. greeniron

    greeniron NES Member

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    Got a question to throw out. I just got done building an AR10 with a PSA upper and an Aero lower. When I put the BCG and charging handle in I cant close it enough to get rear take down pin back. Without the BCG and charging handle it closes up fine. Any advice would be appreciated. Thanks
     

  2. Archilochus

    Archilochus

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    Well, it's a PSA upper - so as usual there's something incompatible between the two.

    What part(s) are interfering to cause the problem - charging handle, bolt carrier, etc?

    Try it with just the BCG installed (no charging handle) and see if it closes.
     
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  3. greeniron

    greeniron NES Member

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    I took out charging handle as you said and it closed as it should have. As it turns out the charging handle is hitting the top rear of the receiver. I imagine that if I have the top /rear of the receiver milled down a bit it should function. after looking at it more closely the same measurement of gap when it was not closing is about the same has the extra height on the receiver, the charging handle is what was keeping it from closing. Thank you for your help.
     
  4. Uzi2

    Uzi2 NES Member

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    If possible, I'd mill the charging handle before I'd alter a lower receiver. If it works, then buy a spare charging handle and mill it.

    Always alter the least expensive or the un controlled part if possible.
     
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  5. Knicks

    Knicks NES Member

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    I had to remove material from my BCM CH to work with my AERO 308 receiver set. I bought the M5 set when it first came out. I don't know if the latest gen have the same problem
     
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  6. greeniron

    greeniron NES Member

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    My Areo 308 M5 lower is brand new, so its the same issue.
     
  7. greeniron

    greeniron NES Member

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    Great point, didn't think of that
     
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  8. Golddiggie

    Golddiggie NES Member

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    Check the charging handle to see how much material is on the underside to remove (and still have it function properly. If the upper and lower are not flush, you might be better off taking some off the lower rather than the charging handle. Simply because if you decide to get a different charging handle later, you'll need to machine that one too.
     
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  9. Uzi2

    Uzi2 NES Member

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    Thats why I said get a spare and have it machined, preferably at the same time.

    If the gun is ever sold and someone wants to put a diffent upper on it, there could be a hideous gap from someone machining it. It would also need a finish on the receiver where its machined and could reduce resale value.
     
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  10. jayhitek

    jayhitek NES Member

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    I had an upper that I had trouble getting the rear take down pin in and it sat flush with the lower..
    So I took the crazy approach to make the holes of the upper a hair larger by filing it with a round file..

    Actually worked. But wasn't my favorite solution.
     
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  11. Uzi2

    Uzi2 NES Member

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    Thats ok as long as it worked, its hidden.
     

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