P-Mag Question

[M4Fundi]

If you are going to have a M4 loaded and left ready to go should you leave a GI Mag in it instead of a P-Mag because of feedlip spread? Or is a P-Mag OK?

How long would it take for a loaded P-Mag's feed lips to spread out of spec with out the covers in place? Any idea?

[chadbag]

Just leave the PMAG in it. Someone mentioned in a thread here a while back having had loaded PMAGs without the cover for well over a year without noticeable impact on the mag.

[Magsz]

I believe Rich fitzpatrick from Magpul posted that.

Ive had loaded pmags sitting around for about 7 months now with zero affect on the feedlips. The go, no go gauge thats build into the cover shows zero spread.

[SWATcop556]

I've had a loaded Pmag in one of my safe queens since they were introduced. This is one of the original ones that I had to shave down a litle bit to drop free.

Since this is definitely not one of my go-to guns I have just left the same Pmag in it. I read this thread so I got curious. Zero spread.

I think it's a none issue, but a good question.

[M4Fundi]

Thanks! I have many high quality mags, but I've learned to really like the feel (and lack of that metallic sound) that my P-Mags offer. I guess I'll just check it with the No Go Cover regularly. I appreciate y'all checking ;-)

[Failure2Stop]

Two comments on this-

1- Feed lip spread is not a concern with PMags. I have had one of the original ones, bought in Dec of 2007, filled with 30 rounds since the day I picked it up, without the cover. No problem at all. If you aren't going to need immediate access, you can put the cover on and eliminate the concern completely.

2- Feedlips can't spread when inserted into an AR with the bolt in the forward/locked position as the top round is pushed slightly down by the bottom of the bolt carrier when the magazine is inserted. You could have a magazine made out of cardboard and the feed-lips wouldn't spead when inserted in a bolt-forward gun (of course everything before and after that would be a problem). I intentionally destroyed a PMag a while ago, and when it had a big crack down the spine it would volcano 2 to 4 rounds if filled to 30. However, if I stuck it into the magwell fast enough the magwell would hold it together and permit faultless function for the full mag.

Anyway, don't sweat it.

[Byron]

Here's the word straight from the horse's mouth (Nick at Magpul) for anyone who wants the post being referenced:

https://www.m4carbine.net/showpost.p...19&postcount=8

[M4Fundi]

FTS Thanks for the info,

I guess forgive my ignorance and contribution to Internet Myths, but I was under the belief (erroneously I guess) that the P-Mag Cover's 1st purpose was to prolong feedlip spread spec life and only as a dust, ding protector secondary.

I am a BIG fan of Magpul products and use MANY, but was under the belief that the P-Mags have many advantages over aluminum, but had one disadvantage of lower feed lip life if under constant load. I "thought" a trainer from this forum posted showing a stack of P-Mags split/cracked at the front of feedlips. I guess I am mistaken and hope I have not contributed to more myth with my question.

[NickB]

FTS Thanks for the info,

I guess forgive my ignorance and contribution to Internet Myths, but I was under the belief (erroneously I guess) that the P-Mag Cover's 1st purpose was to prolong feedlip spread spec life and only as a dust, ding protector secondary.

I am a BIG fan of Magpul products and use MANY, but was under the belief that the P-Mags have many advantages over aluminum, but had one disadvantage of lower feed lip life if under constant load. I "thought" a trainer from this forum posted showing a stack of P-Mags split/cracked at the front of feedlips. I guess I am mistaken and hope I have not contributed to more myth with my question.

If your PMAG feedlips spread/creep, give me a call and I'll replace them all with new ones. As far as I'm concerned, that's a small price to pay for evidence of the first creeping PMAG feedlips to date.

[M4Fundi]

Thanks Nick for being so kind and honorable in how you responded to this thread. It was not in any way meant to knock Magpul and its very innovative and truly quality products. I love the P-Mags and mine are functioning flawlessly. Just wanted to know if there were genuine trade-offs or compromises in using polymer.
Thanks Again!