GUN PMag not loading on closed bolt

Discussion in 'On Topic' started by GearHead, Sep 14, 2009.

  1. GearHead

    GearHead Active Member

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    I bought a bunch of PMags from THT for purposes of constructing 10/30s for the Failstates retarded "high cap" laws. They hold 10 and work great. The only issue I am having is trying to load them on a closed bolt...I figured that since I had added a stick to limit their cap to 10 rds, it probably just didnt have enough room to click into place (rounds too tight or something). So I tried downloading the mags to 9, 8, 7, 6....nothing would load, even when the mags were completely empty.

    And now, come to think of it, my vanilla PMags (unmodified 30 rounders I have in a free state) never were able to load on a closed bolt either...with 30 rounds or empty.

    Am I doing something severely wrong here? I sort of doubt that 7 PMags from THT would all be fucked up...

    For reference, I has a Stag Lower and a CMMG upper, if it makes a difference.

    EDIT: I mean, it's not a big deal to load them with the bolt open and then just hit the bolt stop to load a round...I am more curious than anything.
     
  2. That's an interesting problem. Are there marks on the feed lips like they're hitting something? I can't imagine not being able to seat an empty mag on a closed bolt. Try taking the follower and spring out, and just insert the mag body on a closed bolt. Will it seat properly?
     
  3. GearHead

    GearHead Active Member

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    I know it isn't an issue with the magwell/bolt too, since the POS C-Products 10 round mags I have seat just fine empty or full...

    I'll try your suggestion when I get home from work, MG.
     
  4. Paul Revere

    Paul Revere OT Supporter

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    i've had some trouble loading my 10 round mags on a closed bolt.

    i think its due to the fact that people are so scared about not having an 11th round fit in they make them a little tight, thus resulting in problems with inserting on a closed bolt :dunno:

    note: they are c-product 10/30s
     
  5. THT

    THT The easy way is always mined

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    Through testing, I have found that tolerance between loading on a closed bolt and fitting an 11th round in a PMAG is about 2.5mm. It's why I'm able to make 10/20s and 10/30s that load on a closed bolt but don't fit an 11th round.
     
  6. GearHead

    GearHead Active Member

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    Right...which is why I tried mine with half capacity and/or empty...and they still won't seat.
     
  7. Paul Revere

    Paul Revere OT Supporter

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    yeah, somewhere in that space is the key :dunno:
    :dunno: what to tell you. i dont have much experience with p-mags
     
  8. GearHead

    GearHead Active Member

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    Like I said, it's not realy a big deal either way, I am just kind of curious as to why they won't load closed.
     
  9. Paul Revere

    Paul Revere OT Supporter

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    maybe your lower or mags are out of spec? :dunno: if they wont fit or seat with any number of rounds in them, i'd try a different lower and/or different mags
     
  10. GearHead

    GearHead Active Member

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    It seems unlikely that 7 of them would be out of spec, but I guess it's a possibility. I tried different mags, which DO seat just fine loaded or empty (C Products). I will try seating these on my buddy's CMMG lower.
     
  11. THT

    THT The easy way is always mined

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    I don't think it's the mags as I've made tons of 10rd mags with both the rivet and dowel methods from the same batch that you bought from and they all loaded on a closed bolt :dunno:
     
  12. I'm inclined to guess it's a dimensional issue with the lower. If they won't seat empty it means something is likely hitting something else. Since the follower is able to move when pressure it applied it would make sense that it's not the follower. Since it only happens on a closed bolt, I'd guess it's something that interferes with the carrier. The only thing up there is the feed lip, so that would be my guess as to where the interference happens. Maybe the mag catch is positioned slightly too high and it's forcing the mags to sit a little higher than they should.
     
  13. GearHead

    GearHead Active Member

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    If that was the case, wouldn't ANY mag that I tried to seat have issues on a closed bolt?
     
  14. Not necessarily. The Pmags by virtue of their polymer construction have a different thickness in areas and it's possible that while other mags just barely are able to work fine, the pmag is a hair too big in one way or the other. Really though, everything I've said is just educated guessing and may well be wrong. You'll just have to give it a try and see what happens if you isolate variables. Do you have another lower to try these mags in?
     
  15. The Cable Guy

    The Cable Guy New Member

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    I've never had a problem with the Pmags seating on a closed bolt. I can fit 10 rounds, with some room for some additional space, but not enough to fit an 11th. They seat fine for me :dunno:

    This is the case for the 10/30 I bought from rifle gear, and the two that I made.
     
  16. GearHead

    GearHead Active Member

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    If you take a trip up north I'll let you fondle my magazines :naughty:
     
  17. CharlieMike762

    CharlieMike762 Ride or die...

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    Have you taken this to arfcom? They have an industry section for Magpul and the guys on there should be able to help.
     
  18. GearHead

    GearHead Active Member

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    As much as I despise barfcom, I might have to make an account. Good idea.
     
  19. THT

    THT The easy way is always mined

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    Would they help if it's a modified mag though?
     
  20. GearHead

    GearHead Active Member

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    Meh, I'll just remove the dowel and see if it still happens. If so, then I'll just ship em to my parents in CO.
     
  21. SnakeEater

    SnakeEater OT Supporter

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    Why not do alil light sanding to the dowel?
     
  22. GearHead

    GearHead Active Member

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    As I said before, this happens to ones with the dowel AND without the dowel. They simply will not seat.
     

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