ar-15 bolt catch issue

Discussion in 'AR-15 Discussion' started by RangeRat234, Nov 25, 2011.

  1. RangeRat234

    RangeRat234 New Member

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    After fully assembling my first AR build, the bolt does not go far enough back to engage the bolt catch. I have swapped complete lowers, and my upper works fine. I swapped bolt carrier groups/ bolts.I swapped out buffers and buffer springs in my lower and it will not catch. Any other ideas?

    DPMS lower, DD lower parts kit
    ATI buffer/tube/spring kit (Comm.)
    YHM upper by Precision Firearms
     
  2. Jpyle

    Jpyle New Member

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    Are you saying the bolt doesn't move rearward far enough or that the catch doesn't engage? Do you have an empty mag inserted or are you manually engaging the stop? Did you dry fire the lower, not pinned to the upper" and allow the hammer to hit the bolt catch?

    Pics would help...
     

  3. RangeRat234

    RangeRat234 New Member

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    When manually engaging the bolt catch,the bolt fails to travel far enough rearward to allow the bolt catch to hold the bolt face. 1/8ish inch. The app crashes when I try to add the pic...
     

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  4. Jpyle

    Jpyle New Member

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    Don't know if its the angle but the catch doesn't appear to be seated properly. The catch should appear as a small triangular stub that sits on the magwell rim with a small tail that protrudes into the magwell. When an empty mag is inserted the follower should visibly raise the entire mechanism and capture the bolt as it draws backwards. In the pics it appears that the body of the catch is below where it is needed to engage.

    There are only 2 other places that the bolt can be impeded, the hammer, if installed incorrectly or at an angle may catch on the underside of the carrier or the entire carrier may not clear the buffer tube opening. You would really need to be out of spec for that to happen. You did mention that you have a commericial tube, are all the buffer, tube and spring commercial? Mixing and matching mil-spec and commercial may create a pinchpoint although the parts may appear to fit properly. You may also want to be sure that the buffer is not making contact with any screw in the stock, if the buffer is held up so will the bolt.

    [​IMG]

    Just for the hell of it here's a diagram. The bolt catch spring and disconnector spring are easily confused, check to make sure you got it right.

    [​IMG]
     
  5. mjkeat

    mjkeat New Member

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    I wonder if the buffer is to long.
     
  6. Jpyle

    Jpyle New Member

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    OP says he has switched out spring and buffer. I'm kinda stumped here myself no obvious place for the bolt to hang up unless it's hitting the hammer
     
  7. mjkeat

    mjkeat New Member

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    Thats weird.

    Like you said it could be the catch. Other than that I have no idea.
     
  8. RangeRat234

    RangeRat234 New Member

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    Here are some more pics. Buffer, tube, and spring are all Comm.they came in a kit. No screws to hold up on. Hopefully the pics help ...in the last pic I am pushing the bolt back into the buffer/spring while pushing the bolt catch.
     

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  9. FCross7

    FCross7 New Member

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    Aren't the rifle length buffer springs and carbine buffer springs different lengths? Could it be that he's got a rifle length spring in a carbine receiver extension?

    -Fred
     
  10. FCross7

    FCross7 New Member

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    I just measured the buffer spring in my rifle and it's about an inch shorter than yours, so I'm thinking you have the wrong spring in there.

    Can anyone else confirm this?

    -Fred
     
  11. mjkeat

    mjkeat New Member

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    After reading FC's ost I poped open the safe and grabbed a tape measure. My buffer (Spikes T-2) is quarter of an inch shorter and the spring is nearly an inch shorter than the ones pictured.

    Purchase a mil-spec kit and see what happens.

    It also looks like your mag release is screwed in to far into the button.
     
  12. RangeRat234

    RangeRat234 New Member

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    Thanks for all the ideas...I'll let you all know what happens!
     
  13. RangeRat234

    RangeRat234 New Member

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    Hours of research and more parts swapping later...success! My buffer tube has a notch cut out for the buffer retainer. I unscrewed the buffer tube one rotation, so it barely holds the retainer, and what do you know...the bolt will lock back now. The one rotation was just enough room to let the bolt travel the 1/8ish needed for the bolt catch to engage! So now I will be looking for a buffer tube with a slightly longer lip to hold the retainer better. Thanks again for the help people.
    RR
     

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