AR-15 Help Pmag issue?

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  • SummitCnty

    Ultimate Member
    Jan 26, 2013
    2,223
    Frederick County
    I have an issue with my AR I was hoping some of the resident experts could help with.

    When I load an empty magizine in the well it locks in with no problems. I used Pmag (Gen2 and 3 and 20 and 30 rd) and a couple of other brands. Again, no issues with any of them while the mags were empty.

    Once I start putting more than 3 or 4 rounds into each mag I notice it feels different and locks in different then when the mags are empty. Once I get a full 30 rds in a mag you have to all but slam it in to get it to lock. Is there something I'm missing or not doing right? I don't know whether to look at this as a mag issue or an issue with the weapon. Operator error is always an option.

    Thanks for any insite on this.
     

    amoebicmagician

    Samopal Goblin
    Dec 26, 2012
    4,174
    Columbia, MD
    it's normal.

    The more compressed the spring is, the more resistance it gives when being compressed that last lil bit under the carrier. try it with the bolt open, probably will be fine
     

    Sticky

    Beware of Dog
    MDS Supporter
    Mar 16, 2013
    4,501
    AA Co
    Yep, just get in the habit of smackin the butt on that sucker in and you won't have an issue, bolt opened or not.. ;)
     

    Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,278
    HoCo
    When the bolt pulls back the next round pops up some so the bolt can push the back of the next round forward then up.
    So it stands to reason that if you have a closed bolt that the last few mm in it will hit the top round on the bolt and you gotta fight that pressure.

    Question
    Does a loaded mag make a pmmag swell so it's a bit wider?
     

    DaemonAssassin

    Why should we Free BSD?
    Jun 14, 2012
    23,970
    Political refugee in WV
    When the bolt pulls back the next round pops up some so the bolt can push the back of the next round forward then up.
    So it stands to reason that if you have a closed bolt that the last few mm in it will hit the top round on the bolt and you gotta fight that pressure.

    Question
    Does a loaded mag make a pmmag swell so it's a bit wider?

    The PMAG does not swell when it is fully loaded.
     

    DaemonAssassin

    Why should we Free BSD?
    Jun 14, 2012
    23,970
    Political refugee in WV
    I have an issue with my AR I was hoping some of the resident experts could help with.

    When I load an empty magizine in the well it locks in with no problems. I used Pmag (Gen2 and 3 and 20 and 30 rd) and a couple of other brands. Again, no issues with any of them while the mags were empty.

    Once I start putting more than 3 or 4 rounds into each mag I notice it feels different and locks in different then when the mags are empty. Once I get a full 30 rds in a mag you have to all but slam it in to get it to lock. Is there something I'm missing or not doing right? I don't know whether to look at this as a mag issue or an issue with the weapon. Operator error is always an option.

    Thanks for any insite on this.

    Bolt closed puts stress on the top of the mag, during seating. That explains the resistance you are feeling. If the bolt is open, there is nothing for the mag and ammo to come into contact with, so it will slide in easily, without the need to slam it home.

    Why are you slapping a full mag in on an empty chamber or on a closed bolt?
     

    photoracer

    Competition Shooter
    Oct 22, 2010
    3,318
    West Virginia
    Its because the Pmags all plastic case bulges slightly when fully loaded. Which is why if you store your mags loaded you need to put the "dust cover" on the top. That top is really designed to keep the mags from permanently bulging, the dust cover name is just a cover story and a side benefit. On the otherhand the favorite 3-gun mag, the Lancer L5, has metal lips at the top along with a semi transparent plastic body. It does not bulge, however, you will be hard pressed to get one to lock in place if all thirty rounds are in the mag and the bolt is not open, so most load their 2nd mag with 29 if they plan on doing a tactical reload. Lancers are nice because you can always see how many are in the mag as opposed to the Pmags, windows or no windows.
     

    SummitCnty

    Ultimate Member
    Jan 26, 2013
    2,223
    Frederick County
    Thanks for all the quick answers. Appears it is operator error or lack of knowledge. I'm new to the whole AR thing!!

    Which goes to say I didn't know you were supposed to load it with a open bolt or empty chamber.
     

    clandestine

    AR-15 Savant
    Oct 13, 2008
    37,031
    Elkton, MD
    Load the Mags to 28 and it will be easier to seat on a closed bolt.

    The dust covers do not prevent the feed lips from spreading. It was a HUGE marketing mistake that Magpul has admitted to, and has recanted. They are simply a dust cover, nothing more (They can also be used as a magazine lip gauge too, but that isnt marketed anymore either).

    PMags do not degrade if stored loaded, nor do the feed lips spread.
     

    bkuether

    Judge not this race .....
    Jan 18, 2012
    6,212
    Marriottsville, MD
    Load the Mags to 28 and it will be easier to seat on a closed bolt.

    The dust covers do not prevent the feed lips from spreading. It was a HUGE marketing mistake that Magpul has admitted to, and has recanted. They are simply a dust cover, nothing more (They can also be used as a magazine lip gauge too, but that isnt marketed anymore either).

    PMags do not degrade if stored loaded, nor do the feed lips spread.

    This. I go one more to 29 and, on my guns anyway, it is fine. YRMV.
     

    SummitCnty

    Ultimate Member
    Jan 26, 2013
    2,223
    Frederick County
    Load the Mags to 28 and it will be easier to seat on a closed bolt.

    The dust covers do not prevent the feed lips from spreading. It was a HUGE marketing mistake that Magpul has admitted to, and has recanted. They are simply a dust cover, nothing more (They can also be used as a magazine lip gauge too, but that isnt marketed anymore either).

    PMags do not degrade if stored loaded, nor do the feed lips spread.

    Excellent.

    Thanks to everyone!
     

    amoebicmagician

    Samopal Goblin
    Dec 26, 2012
    4,174
    Columbia, MD
    Its because the Pmags all plastic case bulges slightly when fully loaded. Which is why if you store your mags loaded you need to put the "dust cover" on the top. That top is really designed to keep the mags from permanently bulging, the dust cover name is just a cover story and a side benefit. On the otherhand the favorite 3-gun mag, the Lancer L5, has metal lips at the top along with a semi transparent plastic body. It does not bulge, however, you will be hard pressed to get one to lock in place if all thirty rounds are in the mag and the bolt is not open, so most load their 2nd mag with 29 if they plan on doing a tactical reload. Lancers are nice because you can always see how many are in the mag as opposed to the Pmags, windows or no windows.

    that mag swelling is a myth, i have left mine loaded for years.

    Lancer mags are however much better all around, regardless. They function flawlessly even in problematic rifles and are just plain amazing.

    The clear and smoke colored ones are the most durable, somehow. Made of bullet proof glass material. There are some OUTRAGEOUS torture tests on them. I have a bunch of the smoke and clear ones, and a few opaque black. There is a good reason the sig MPX mags are lancer translucent mags.
     

    MKR03

    Active Member
    Apr 1, 2014
    675
    State of Montgomery
    Would it be safe to say on a 20rd mag go 18 and on a 10 rd go with 8

    Yep. I load all my mags to 2 less than "capacity." When you insert a mag with the bolt closed you have to apply a little more force than with the action open, but either way you shouldn't have to smack or slam them in too hard. Just push then pull.
     

    DaemonAssassin

    Why should we Free BSD?
    Jun 14, 2012
    23,970
    Political refugee in WV
    Thanks for all the quick answers. Appears it is operator error or lack of knowledge. I'm new to the whole AR thing!!

    Which goes to say I didn't know you were supposed to load it with a open bolt or empty chamber.

    Since you are in my neck of the woods, we can link up and have a bull session some time. My brain is yours to pick. I also have tools to build. :D
     

    songlaw

    Active Member
    Aug 2, 2017
    240
    Clarksville
    PMAG Problems, continued

    Good morning.
    This crisp morning, I shot a fully loaded 30 round PMAG Gen 2 MOE mag. I released the mag, loaded another, and the mag would not catch. Tried a bunch of others, with the same result.

    I read the earlier posts, and shoving with some force appears to have done the trick.

    Anyone know if the same issues exist with the Gen 3 PMAGs?

    Is it just a matter of being more forceful during insertion of the mag?
     

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