View Full Version : Pmags failing to feed -- NOW WORKING ! ! !
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).
Is the rifle short stroking?
I like the P mags, and mostly run them, but I still think there's some hit and miss problems with them.
I bought two twenty round ones lately and one feed fine and the other one won't begin to function.
I'd make sure you're at least getting the latest generation of P mag.
RetreatHell
11-18-09, 12:34
Is the rifle short stroking?
That's what I was thinking.
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.
1) What upper/lower are you using?
2) What buffer are you using?
3)what ammo are you using?
Is the rifle short stroking?
That's what I was thinking........Don't be so fast to blame the PMAG for this, as it sounds to me like your rifle is short stroking......
From the original post:
.......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.....
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.
.....with XM193......it cycles fine......Some ammo is just under powered, and it is probably causing your rifle to short stroke.
.......
Forgot to include earlier, Pmag hiccups happened while using XM193.
Failure2Stop
11-18-09, 13:18
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.
.....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........
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 would check the function of the gun with other "known good" mags from your stockpile and see if the problem persists........
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.
My next question is going to be this; Have you attempted to contact Magpul yet and discuss the problem before you posted it here?
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.
My next question is going to be this; Have you attempted to contact Magpul yet and discuss the problem before you posted it here?
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.
10 kelvin = -441.67 degree Fahrenheit
Will PMags really go that cold?
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.
Good Luck.
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....
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%.
10 kelvin = -441.67 degree Fahrenheit
Will PMags really go that cold?
Perhaps, but people can't. :D
I've had one break, but it was from purposeful abuse. I wanted to see how much it could take... and it took a lot!
Gutshot John
11-18-09, 15:50
Mmmm I wonder if a rehash of the process for properly seating the magazine might be in order.
Beer can, Push-Pull anyone?
RetreatHell
11-18-09, 16:11
From the original post:
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).
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.
BTW, good luck at your match this weekend!
-Paul
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.
10 kelvin = -441.67 degree Fahrenheit
Will PMags really go that cold?
Do PMags have a Hi/Lo Temperature Rating?
RogerinTPA
11-18-09, 19:58
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.
.......OVERNIGHT UPDATE.......
(But first, thanks everybody for all the good feedback -- I'm feelin' the luv. :D)
(Also for the record, these are four 30-round Pmags in FDE.)
After work yesterday I went over the mags in detail, with the following results:
(1) As assembled, the spring and follower in each mag appears to travel without any stickiness (as tested by slowly pressing downward with the end of a ruler). This was found to be true both empty and holding various quantities of ammo in 5-round increments.
(2) The mags were then disassembled. Right away I was surprised to find how dirty the springs were in these brand new mags (I have only shot a single mag-full of ammo through each one so far). My hands were covered in black by the time I had all four taken apart. First thing I did was to wipe down all four springs thoroughly.
(3) Flashing doesn't appear to be an issue. The interior of each mag body is clean and smooth.
(4) Follower-to-body fit was then tested without any spring tension. The followers fit loosely along most of their travel paths in all four mags. On three of the mags, the follower slightly snug-ups up gradually within a half inch to an inch of the feed lips. On the fourth mag though, there is a more abrupt grab at a point about two inches down from the feed lips. Switching among follower and bodies showed that the cause was from the follower and not the body. The effect isn't really noticable under spring tension, so I'm not sure this is anything significant other than showing that the mags are not exactly identical.
(5) With the mags re-assembled, I tested their fit to the rifle. All seemed to seat about the same, and not noticably different from my GI mags. The feed lips also appear to be clearing the bolt OK.
After all this, it was too late in the day to try calling Magpul. I am first going to take everything back to the range though (hopefully tomorrow afternoon), to investigate further under live-fire conditions. It would be good if I could clear this up without having to hassle with getting Magpul to provide replacements.
One thing I want to test on the seating question, is whether any difference takes place between inserting the mag with bolt open and then closing from slide lock, versus inserting against a closed bolt and then cycling the bolt to chamber the first round. The latter procedure might preclude a full seat.
......Dirty/dusty tubes and followers can cause the round stact to rise too slowly for the bolt to pick up the next round.......
After reading this, I recall from my first time with these mags a couple of shots that were followed just a moment later by a distinct "ker-chunk", feeling very much like a stack of rounds jumping up after clearing a snag. Something else I need to look for again.
If I'm lucky, maybe all of this trouble was just the result of those dirty springs. Shall report back after the range trip.
Check the Pmags for ANY flash on the follower. Look at any edge that can touch the mag tube. This has been a particular problem with the 20 rd Pmags IME.
I use a cheap plastic paint mixing stick (looks like a ruler) to work the follower full range in any mag I use to see if there is a sticking or rough point.
Not feeding the next round can be short stroking or delayed mag lift of the cartridge.
If a mag is hard to insert loaded to capacity don't fight it - just load it down one round. Manufacturers often rate mag capacity assuming open bolt. Closed bolt requires a down load.
I believe p-mags are designed to carry a full load of ammo and still seat on a closed bolt.
I agree. All of my Pmags seat fully loaded. However given a particular gun mag combo one never knows.
Well after cleaning up those cruddy springs, another full batch through each Pmag was digested without hiccup at the range Friday afternoon. I seated each mag with the bolt open though. Back home, I again took the Pmags apart and gave the springs a second rub-down, this time with lots of CLP applied.
With a gulp then, I also used the Pmags at Sunday's match, and again without problem. Also again, seating was on an open bolt.
From the maker, the springs came with a heavy layer of gummy residue. I can see how adjacent loops could have been adhering to each other with the spring fully depressed. Of course, far more use is needed to establish complete reliability, but hopefully the issue is now resolved.
Any future Pmags will be dissembled and cleaned thoroughly before being put into service.
Robb Jensen
11-23-09, 07:08
If they're using chrome-silicon springs they sometimes have this weird sort of grease on them. For my 10" suppressed gun and my old 3gun rifle (adjustable gas with a lightweight carrier) I use PMAGs with Wolff +10%XP springs.
With my new barrel on my 10" gun (small gas port, LMT enhanced carrier, H buffer) and my 2 new 3gun rifles (midlengths with regular non-adjustable gas blocks and M16 carriers) I don't need the stronger springs anymore but I left them in there so they work even really well when extremely dirty. On my mags I use for training and the 10" gun I drill a hole in the Magpul logo and keep the dust cover clicked onto the bottom of the mag to prevent dirt/mud from getting up into the hole. This converts the mag to their maritime style. This allows water or gas to escape the bottom of the magazine.
......I drill a hole in the Magpul logo and keep the dust cover clicked onto the bottom of the mag to prevent dirt/mud from getting up into the hole. This converts the mag to their maritime style. This allows water or gas to escape the bottom of the magazine.
Good tip.
Heavy Metal
11-23-09, 11:57
Make sure you aren't putting 31 rounds in them. The mag will 'barely' accept 31 rounds and this can cause problems.
Ga Shooter
11-23-09, 12:13
What size hole do you drill into the mag?
Thomas M-4
11-23-09, 19:47
What size hole do you drill into the mag?
I used a center punch heated it up with a lighter and put a dimple in the center of the magpul logo to keep the drill bit from walking. Drill bit sized I used was 1/4''.
Glad you were able to diagnose the issue and correct it Randy.
How about changing the title to something a wee less dramatic..... :D
.......How about changing the title to something a wee less dramatic..... :D
The Pmags were part of an overall Magpul makeover of my M&P, and that included their new handguard along with the MOE pistol grip and buttstock, all in FDE. I was disheartened when encountering problems with the Pmags, but likewise excited when it appeared they had been fixed.
The overall set-up now is pretty nice looking, and likewise to shoot (it was the feel of that new handguard that prompted the project). Was used to good effect at last Sunday's IDPA side match. I need to get some before-and-after pics to add to the appropriate thread here, hopefully over the upcoming holiday.
P.S. I also added one of those Blue Force Gear slings, as you recommended Tim -- great item.
ThirdWatcher
11-24-09, 06:28
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 think some of the early M&P-15's had tighter magwells, but S&W fixed this when it was brought to their attention. My campanion is #SW60XXX and it loves Pmags.
Ga Shooter
11-24-09, 07:38
I used a center punch heated it up with a lighter and put a dimple in the center of the magpul logo to keep the drill bit from walking. Drill bit sized I used was 1/4''.
Thanks for the info.
CarlosDJackal
11-24-09, 14:02
From the original post:
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).
Who made the lower? I'm inclined to think that there may be an issue with the spec. My SGW/Olympic Arms lower didn't like PMags either.
However, any of my lowers that were made to spec (RRA, TKS Engineering, Raggio Arsenal, and Bushmaster) has no problems with the. Even my Kel-Tec PRA-16 Pistol likes them. YMMV.
CarlosDJackal
11-24-09, 14:05
I believe p-mags are designed to carry a full load of ammo and still seat on a closed bolt.
To clarify, a "full load of ammo" is 30-rounds for the 30-round version and 20-rounds fro the 20-round version. I can regularly insert 31 and 21 respectively if I don't pay attention when loading.
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.
Two live rounds being loaded or one live round and a spent round?
RogerinTPA
11-25-09, 20:03
Two live rounds being loaded or one live round and a spent round?
Two live rounds, with 2 mags and two live rounds and a stuck case with the other two. New mags, with two different batches of 12 new Pmags. With the stuck cases, I thought it was an extractor issue, but the odd thing is, I ran 3 mags prior and 7 mags right behind them, without issue. The 2 others mags would repeatedly double feed, but I ran 5 mags behind those two, also without issue.
One was noticeably a spring issue. When I loaded it to 30 rounds, and started manually removing the rounds, occasionally, the spring would not move, without slapping the side. I'll disassemble them, look for flashing issues, debris, clean and lube, then try them again this weekend.
I was having a similar problem, I'll check my springs.
Great thread - Of quite a decent selection of Magpuls I have 1 that has given me problems - simply chalked it up to the gods of probablilty that there is an anomally from time to time. Now I got a buddy with an XCR who has two that just wont do-it(double feeds at about round 15-18) but functions fine in his ARs - will definate try this one our and pass on to him
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