I had always assumed Pmags were completely reliable, but the few I recently bought are occasionally failing to feed. The spent case ejects OK, but then the bolt closes on an empty chamber. Happens 1 or 2 rounds per mag.
The gun has a well established record of reliability with GI-spec mags, so I’m pretty sure this flare-up is from the Pmags.
Anybody else experience this? Any idea how? At one point it felt like the Pmags might have been having trouble seating full in, but I’m not sure (need to shoot some more to check further on this).
When using Wolf ammo in an upper I have, if I use an H2 buffer or heavier buffer in the lower, it will eject the spent casing but not have enough “umph” to chamber the next round simply because the Wolf ammo is underpowered (note that every batch of Wolf ammo can net different results too). Basically, it can’t fully drive back the heavier buffer enough to where the bolt catches the ass end of the next round in the mag to be able to shove it forward and chamber it. The bolt will simply slide over the next round in the mag and when I pull the trigger I get a “click.”
Once I put an H1 or carbine weight buffer in the lower, the carbine will function fine with Wolf.
Don’t be so fast to blame the PMAG for this, as it sounds to me like your rifle is short stroking.
What upper/lower are you using?
What buffer are you using?
3)what ammo are you using?
The “well established record” includes all kinds of ammo including lots of Wolf. After some trouble early-on with this rifle that quickly led to getting the BC key re-staked, it has since shot thousands of rounds flawlessly…until getting these Pmags (the current version ordered directly from Magpul).
as retreat hell stated I have the same problem. Rem UMC 55gr doesnt have enough “power” to cycle my SBR with the H2 buffer or even my Carbine buffer. But with XM193(any of its manufacturers), M855, and even some PMC 223 55gr it cycles fine with the Carbine buffer.
Some ammo is just under powered, and it is probably causing your rifle to short stroke.
edit - you posted while I was typing. You may have some fluke Mags then.
It is possible for magazines to be the cause of failures to feed.
Dirty/dusty tubes and followers can cause the round stact to rise too slowly for the bolt to pick up the next round.
Worn springs can also be to blame.
It is possible that plastic flash inside the mag may be impeding movement of the follower or round stack.
While PMags are my favorite mags and my go-to mags for any environment over 10 degrees Kelvin, they are not exempt from the possibility of not working right. All magazines should be considered to be disposable, which is one reason for me that the price-point of the PMag is so enticing. It was pretty hard to convince people 4 years ago that there could be anything wrong with their $60 HK mags :rolleyes:.
I would check the function of the gun with other “known good” mags from your stockpile and see if the problem persists. If not, take the PMags apart and give them a good scrubbing, ensuring that all flash from the molding process inside the tube is removed and not causing any drag on the follower and that the magazine is properly reassembled.
If that does not fix the issue contact MagPul and see what they have to say.
Thanks – I do need to spend more time examining the Pmags in detail. They are brand new from the maker, so dirt or wear shouldn’t be a factor. I hadn’t thought of flash though. I need to check closely for spring and/or follower bind along the path of movement.
I have a match this Sunday that I was hoping to bring all the new Magpul stuff to (at the same time as the Pmags I also got a new MOE handguard, PG, and buttstock), but it looks like I’ll be using the old, ugly-but-reliable GI mags.
Well, no…:rolleyes:…but now shall, having been shamed into it.
I don’t wish to besmirch a product without warrant. My intent in making this post was to see whether the problem has been previously seen among shooters. Again, I am very surprised that Pmags should have any problem. Also, I thought I had seen a post several months ago, to the effect of various mags seating differently in various receivers (which is the only explanation for the current problem that I have been able to come up with). BTW – the subject rifle is an M&P.
I’ll call Magpul later today and report back here.
Yesterday, at the range, I loaded a P-mag. Pulled the charging handle of the rifle. Got down on the sights. Pulled the trigger and nothing happened.
Pulled the charging handle again. Got down on the sights. Squeezed the trigger and nothing happened. Pulled the bolt open slightly to observe and found no round in the chamber.
WTF? Looked at the rifle. Opened and locked the action. It was then I noticed the p-mag still sitting on the shooting bench.
Duh. I find it hard to laugh at myself, but had no hesitation doing so at this situation.
The point is, those p-mags are pretty soft when locking into place. Is it possible…
one way to find out… take it into space and fire off a few rounds lol
Since I live in NJ I had to buy PMAGS that were “NJ legal”, IE rigged to run only 15 rounds. With all 15 rounds in them, I have to slap the bottom of the magazine pretty damn hard to get it to seat. At the range I had a few instances where a round would not feed only to find that even though the magazine was in the mag-well and did not fall out, it was still not fully seated. Even when fully seated because of the polymer construction I would not hear a “click” like I would with the metal magazines making it dificult to know if it was in all the way without pulling on the magazine.
Once I made sure the PMAG was in all the way, I never had an issue again.
I know you have unmolested PMAGs, but maybe with all 30 rounds in it, being new and having the spring be new, it may take a bit of a slap to have to seat them all the way.
Im still a HUGE noob at all of this, but I would veture to guess that is the problem.
Like a couple guys said, you need to check to see if there is any flashing still inside the mag tube. I bought three Pmags at the end of last year and when I was loading them, it seemed like the rounds weren’t seating right. Upon further inspection, there was some flashing that basically was sitting under the rear of the feed lips. This was pushing the rims of the cases down and possibly out of the reach of the bolt face. I noticed this before I shot them, but I’m sure the potential for a failure to feed was there. Five seconds and a razor blade and the flashing was gone and they have been 100%.
Roger that. It very well could be the PMAGs that are the problem, as occasionally you here stories from guys who had bad luck and bought a few PMAGs that had some flaws, in which case Magpul (being the awesome company that they are) quickly replaced the mags for them. All you have to do is contact them and let them know, then either they will mail you however many mags and include a return shipping label in the box, or you will simply mail them your mags and once they receive them they’ll ship you some new ones. I had to do that with an MBUS rear sight that broke while installing it, and they quickly replaced it without question.
But I still think it’s possible that it might not be the PMAGs. I’m not insinuating anything about you, your knowledge, your skills or your S&W carbine… just saying that the PMAGs might not be the problem and you might just be assuming that they are. I know that PMAGs used to not work in the older M&P15’s, but I’m not familiar as to why that was, so someone else who knows more about that would have to chime in.
I’ve personally seen a DPMS AR15 that would NOT work with any of the owner’s PMAGs. They would not seat in the mag well, and the owner assumed that his DPMS mag well was just out of spec or something. But his AR worked fine with GI mags and they seated usually every time.
Did all of the PMAGs you just bought have this problem? How many did you buy anyways?
Have you tried running these same PMAGs in a different carbine, or just this one? If I were you, before I contacted Magpul I would at least try running them in a different AR if you have access to one. Or you could always just go to the range and find some random person and ask them to help you out by loading up a few or their rounds in your PMAGs and then just see what happens.
Like I said, it could always be the PMAGs themselves, but I’d personally do some further testing before I called Magpul to get them replaced.
I actually hope the problem is with the PMAGs, as that would be a far better outcome for you. Regardless of what happens, I hope it all works out for you.
I had a couple that induced double feeds this weekend (several times) and two others the previous weekend, using 2 separate AR’s (LMT and 6920). They were brand new, right out of the bag. I will check my other new Pmags for proper function before giving Magpul a call. I have 100 of them (60 have never been used), so this may take a while. I’ll also check the innards of the bad mags for flashing issues as well. I can always fall back on my aluminum mags, but I was a bit surprised at brand new mags doing this.
