Trouble with AR pmags?

[Reaper]

I recently bought a used AR. I'm not sure if it's a mag issue, or if there's something wrong with the rifle.

 

Empty PMAGS seat and click in just fine. Loaded PMAGS sometimes do not seat or click in. Two mags in particular do not seat.

Do you think this is a fault with the mags...or the rifle?

 

No, I haven't shot it yet.

[TRJ]

Down load by 2, full magazine is 28 for anyone who might have to load on a closed bolt.

[jpearson]

All magazines if fully loaded are difficult to seat with the bolt forward.

I load all my ar magazines to 28 rds.

To make sure i can insert them with bolt forward. Fully loaded 30 rd should only be loaded with bolt all the way to rear.

[Gamma]

Yes, if you fully load any magazine it cannot seat on a closed bolt.

 

PMags will generally accept 31 rounds due to the number of clueless people who go nuts if they can't load their "30 round magazine".

 

But if you just load it until it won't accept any more rounds, which is probably 31, it won't load on a closed bolt.

 

This is just the mechanical reality of dual position feed magazines.

 

Load it fully then remove at least one round.

 

Fully loaded 30 rd should only be loaded with bolt all the way to rear.

Fully loaded magazines should not be loaded regardless of whether the bolt is to the rear. In some circumstances, the first round cannot move correctly during the feeding process and may induce a malfunction.

[DD123]

I experienced the issue and it seems to be very dependent on the bolt carrier itself. My RRA chrome BCG seems to have difficulty getting a fully loaded Pmag to seat unless you slap the heck out of it, while the titanium BCG I'm running in my 3 gun upper has no problems whatsoever. I have 30 round Pmag's with the Taran Tactical extensions, which allow me to load 35 rounds, and there's literally no room left. You can take a round and press down, but the 35th round in the mag won't even move.

 

Both of these uppers were on the same lower, which leads me to believe that it's the BCG itself that causes the issue. Luckily after experiencing that malfunction on a 3 gun stage last year, I've tested all of my mags to make sure they go in with no more effort than pushing the mag in.

[Reaper]

Ive never experienced this before. I've had several AR's in the past, loading a full mag into a closed bolt is always hard. But, this is different. An empty mag will seat and click in just fine. Even if I load only 4 or 5 rounds into the PMAG, it won't seat. Some times it will. Sometimes it won't. I'm gonna try different mags. I just hope it's not the rifle.

[DD123]

Ive never experienced this before. I've had several AR's in the past, loading a full mag into a closed bolt is always hard. But, this is different. An empty mag will seat and click in just fine. Even if I load only 4 or 5 rounds into the PMAG, it won't seat. Some times it will. Sometimes it won't. I'm gonna try different mags. I just hope it's not the rifle.

Do you have a magazine funnel on the magwell by chance?

 

If so, which one, and which generation of Pmag.

[skinnyb82]

Could it be a mag catch issue? Had a catch that would sometimes grab the mag, other times it wouldn't when the mags were fully loaded. That was on my 6.5mm with ASC/C-Products mags but same principle applies.

 

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[luckydawg13]

I got away from P mags and switched to http://www.brownells.com/magazines/rifle-magazines/magazines/ar-15-20rd-magazine-cs-223-5-56-prod71747.aspx

[Reaper]

 

Ive never experienced this before. I've had several AR's in the past, loading a full mag into a closed bolt is always hard. But, this is different. An empty mag will seat and click in just fine. Even if I load only 4 or 5 rounds into the PMAG, it won't seat. Some times it will. Sometimes it won't. I'm gonna try different mags. I just hope it's not the rifle.

Do you have a magazine funnel on the magwell by chance?

 

If so, which one, and which generation of Pmag.

 

 

 

No funnel. They're gen2 pmags, I believe.

 

I'm going to buy a couple brand new gen 3's tomorrow, see if that makes a difference. I can understand why a fully loaded mag wouldn't seat, but a mag with only 4 rounds? And, if the mag is empty, it seats fine.

[DD123]

 

 

Ive never experienced this before. I've had several AR's in the past, loading a full mag into a closed bolt is always hard. But, this is different. An empty mag will seat and click in just fine. Even if I load only 4 or 5 rounds into the PMAG, it won't seat. Some times it will. Sometimes it won't. I'm gonna try different mags. I just hope it's not the rifle.

Do you have a magazine funnel on the magwell by chance?

 

If so, which one, and which generation of Pmag.

 

 

 

No funnel. They're gen2 pmags, I believe.

 

I'm going to buy a couple brand new gen 3's tomorrow, see if that makes a difference. I can understand why a fully loaded mag wouldn't seat, but a mag with only 4 rounds? And, if the mag is empty, it seats fine.

 

Perhaps check the mag catch like skinnyb recommends. Maybe it's faulty and needs to be replaced, or needs to be screwed in a bit more?

 

The reason I brought up the mag funnel is because I had one on mine from that Israeli company (Fab defense maybe?) and it worked fine with gen 2's, but not with gen 3's. I had to pull it off and grab the one shooter's connection sells.

 

The mag catch seems the most likely culprit at this point, so it's probably worth it to rule that out before spending more money.

[ScopeEye]

There are/is issues with Gen 3 Pmags with some Lowers

Have a look
https://www.youtube.com/watch?v=dlJx5tR4jog

[Windermere]

Lock bolt back and insert full mag

[Trevis]

I load 30, and just give the bottom of the mag a hard slap. Works fine. Take the upper off and see if the interference is on the lower.

[Glock23]

I load 30, and just give the bottom of the mag a hard slap. Works fine. Take the upper off and see if the interference is on the lower.

I do the same, but my Tavor prefers gen 3 PMags vs gen 2. The gen 3s don't require a slap.

 

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[Reaper]

 

 

 

No funnel. They're gen2 pmags, I believe.

 

I'm going to buy a couple brand new gen 3's tomorrow, see if that makes a difference. I can understand why a fully loaded mag wouldn't seat, but a mag with only 4 rounds? And, if the mag is empty, it seats fine.

 

Perhaps check the mag catch like skinnyb recommends. Maybe it's faulty and needs to be replaced, or needs to be screwed in a bit more?

 

The reason I brought up the mag funnel is because I had one on mine from that Israeli company (Fab defense maybe?) and it worked fine with gen 2's, but not with gen 3's. I had to pull it off and grab the one shooter's connection sells.

 

The mag catch seems the most likely culprit at this point, so it's probably worth it to rule that out before spending more money.

 

 

 

 

You think the mag catch may need one more spin? I've owned half a dozen or more AR's, never had this issue before.

[skinnyb82]

 

You think the mag catch may need one more spin? I've owned half a dozen or more AR's, never had this issue before.

This exact thing has happened to me. The mag catch was simply too loose. I was driving mags into the mag well and they wouldn't seat properly. Tightened the catch one turn, problem solved. This was when I was using fully loaded Grendel mags with a closed bolt. That being said, the mag wouldn't always seat properly regardless of the amount of rounds in it but the problem was that the lighter the mag (fewer rounds), the more likely it was to stay in the mag well. The weight is what would drop the mag. Not saying this is the culprit but it's a lot cheaper to replace a mag catch (if that is the culprit) than to go looking for "zebras" and start replacing the more expensive parts. Sent from my VS987 using Tapatalk

[Reaper]

 

You think the mag catch may need one more spin? I've owned half a dozen or more AR's, never had this issue before.

This exact thing has happened to me. The mag catch was simply too loose. I was driving mags into the mag well and they wouldn't seat properly. Tightened the catch one turn, problem solved. This was when I was using fully loaded Grendel mags with a closed bolt. That being said, the mag wouldn't always seat properly regardless of the amount of rounds in it but the problem was that the lighter the mag (fewer rounds), the more likely it was to stay in the mag well. The weight is what would drop the mag. Not saying this is the culprit but it's a lot cheaper to replace a mag catch (if that is the culprit) than to go looking for "zebras" and start replacing the more expensive parts. Sent from my VS987 using Tapatalk

 

 

 

I forgot to mention, the empty mag doesn't always drop free, either. You think that's a mag catch issue? It's weird, an empty mag seats and clicks in fine. If I load 5 or 6 rounds into the same mag, it won't seat.

[splash]

I forgot to mention, the empty mag doesn't always drop free, either. You think that's a mag catch issue? It's weird, an empty mag seats and clicks in fine. If I load 5 or 6 rounds into the same mag, it won't seat.

Mag catch too tight? Try loosening it.

[DD123]

 

I forgot to mention, the empty mag doesn't always drop free, either. You think that's a mag catch issue? It's weird, an empty mag seats and clicks in fine. If I load 5 or 6 rounds into the same mag, it won't seat.

Mag catch too tight? Try loosening it.

 

Yep, trying tightening first, test it out. If that doesn't do anything, try loosening it back to where it was, then another spin.

 

You mentioned that it was a used AR, so the person that owned it before could have not installed the mag catch properly, or used something that wasn't built to spec.

 

One other thing you can do to eliminate possibilities is if you have another AR, stick that upper on the lower that you're having problems with, and see if it seats. Then take the upper from the problem AR, and put it on your properly functioning lower.

 

If you don't have another AR, ask a friend to bring theirs over. Try the same mag in their AR to see if it first seats, and then swap uppers and lowers to test.

 

All of this costs nothing so IMHO it's worth testing to figure out where the problem is. Who knows, it might just be that the mag catch needs to be tightened or loosened.

[skinnyb82]

The added weight of a few rounds might be the reason why the catch is catching and releasing the mag because it simply isnt tight enough to grab the mag and hold onto it. Try seating an empty mag and then tug on it and jiggle it from the base plate area. If the catch is way loose then it'll likely come out without much force. I've also installed one too tight and that SOB wouldn't let the mag go without a fight.

 

As DD said, try swapping uppers if you can. It could be an upper/lower "mating" issue. I've never had it happen to me but I do know some manufacturers have QC issues or the lower (or upper) could be part of a bad batch.

 

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