pmags wont seat

[Boboclown]

Id actually like to get a couple USGI spec mags...

IMO everyone should have some USGI mags, both 30s and 20s.

 

[Koda]

From Magpul:

It's indeed called an over-insertion stop, but the reality is that it serves that function in ways that aren't as obvious as the name implies. Yes, it prevents over-insertion on an open bolt reload, but the M2 had such a mechanism, also...just on the front of the mag. Due to HK adopting the SA-80 magwell front dimension, the front stop had to be lowered, like on the E-Mag. The rear stop serves that function on the M3, but the reality is...you really have to be a gorilla to over-insert even an E-Mag into an AR, which has no stop at all, let alone an M2. The actual reload insertion part was something that did indeed happen once in a blue moon, but preventing this was very secondary to the primary functions of the stop.

The primary function of the stop is in impacts to the bottom of the magazine in loaded weapon drops, or practical applications of this, such as going prone in a less than controlled manner, magazine monopod bearing down on the rifle, impacts during handling, etc. Lots of folks want to emphasize feed lip drops, and they are very important, but the reality is that impacts to the bottom of the magazine when in the rifle are probably more likely and more violent due to the weight of the rifle. USGI mags and other metal mags can buckle the mag catch area under such impacts, catching the follower or round stack and rendering the magazine completely non-functional, and polymer designs without some form of an effective stop (polymer of any kind will give more) can slip past the catch under such an impact and stop the rifle up, hard. All Magpul AR PMAGs have this feature, in some form, that works in the platforms the magazine was designed to fire in. (E-MAG lacks this feature unless in an SA-80 or HK416) This stop also prevents overriding the mag catch under aggressive magazine monopod operation, which can alter feed geometry enough to induce a stoppage in extreme cases. (Interestingly enough...if you have a polymer mag that is supposed to have super tough feed lips...fire it from magazine monopod and put some lateral pressure on it...fore, aft, side, whatever. Ruh roh. Not stiff enough. But, I digress.)

There are indeed a white buffalo number of "in-spec" USGI pattern receivers that are tight with the dimensions of the stop location, generally when coupled with mag catches that are at the ends of the spectrum, and either ride up prior to snapping in because they are small, or require a more complete insertion because the catch itself is large, either of which, when coupled with a long rear mag well dimension at the ends of "acceptable", can interfere. Yes, you can find a few online, but this percentage is so small as to be infinitesimal compared to the numbers out there. Changing the catch usually works, and if not, a file stroke or two to the tab will solve the problem on the primary mags, and an unaltered mag usually inserts with a tiny bit of fore/aft rocking if an unaltered mag is picked up. Alternatively a couple thou off the offending receiver edge fixes it once and for all, though most will not want to break through the ano on a lower to do this.

The whole goal with the M3 was to increase durability even over the combat-proven M2, but also to be the most reliable magazine, period. We have proven this over hundreds of thousands of rounds, (hopefully some of the third party data will be released to the light of day at some point) in fixture tests, etc., and where the M3 really shines compared to other options is after being beaten around a bit, dirty, field conditions, etc., whether facing softer polymer mags, metal, etc., whatever. The over-insertion stop is part of this line of reasoning around field condition performance.

here is a direct link to the quote above from Magpul rep: Problem with a new BCM lower - Page 4

 

[DirectDrive]

Id actually like to get a couple USGI spec mags...

In my post #13 there is a link to 44Mag....a good mag supplier and Oregon-based, I believe.
The Okay, NHMTG and Colt marked mags typically all come out of the same New Britain, Conn. plant.
44Mag has the Okay and NHMTG.
CAGE code 33710 (Okay) is a USGI M4 mag.
The (gray) Dryfilm Finish is slick and just looks like a combat mag.
There is a new EPM mag that I haven't seen yet.
BREAKING: US Army Introduces New Enhanced Performance Magazine for M4/M16 Series Rifles - The Firearm Blog

First they were used, then banned and now approved...
<broken link removed>

 

[Koda]

hit em with a file and they work fine. Thanks everyone for the tips and solution saved me the hassle of replacing them.

 

[DirectDrive]

View attachment 334528

hit em with a file and they work fine. Thanks everyone for the tips and solution saved me the hassle of replacing them.

Glad to see you got it fixed !

I have some USGI 30 rd NIW (new in wrapper) M4 mags inbound from a seller that I have used before.
They are marked "Okay" (brand) cage code 33710 dated 3-12
They were $10 ea shipped.
Seller likes to use PayPal.
He has 10 left.
PM me with your email and I will put him in touch if you are interested.

 

[Koda]

Glad to see you got it fixed !

I have some USGI 30 rd NIW (new in wrapper) M4 mags inbound from a seller that I have used before.
They are marked "Okay" (brand) cage code 33710 dated 3-12
They were $10 ea shipped.
Seller likes to use PayPal.
He has 10 left.
PM me with your email and I will put him in touch if you are interested.

View attachment 334719

thats ok but thank you. I did place an order on 44mag already actually.

Brownells has their USGI version on sale for $10 each right now, are those the same or as good?

 

[DirectDrive]

thats ok but thank you. I did place an order on 44mag already actually.

Brownells has their USGI version on sale for $10 each right now, are those the same or as good?

I don't have an opinion on the Brownells USGI mags.
If they are the real deal then they would probably be from that New Britain, Conn. plant where most of the genuine stuff seems to come from.

 

[Boboclown]

Brownells are decent from what I hear. For 20s; however, I stick to Okay and NHMTG (same company really) as Brownells 20s don't look like the milspec 20s.

 

[HB of CJ]

Back in the day, (1985) lots of sub contractors made USGI 30 rd aluminum mags. The base plates came from Colt and were thus marked. OK Machine out of OK. (I think) made mags for Colt. Colt then put their name on them but the manufacture was not Colt.

The bottom line is that if a USGI 30rd aluminum fits and feeds then you are good to go. My current understanding talking around is that the Brownells contract USGI mag with the brown followers are outstandingly good. Confirmation? Respectfully.

There is also an old mag trick lost in the midsts of time and space to correct function with mags using the crappy horrible early design followers. The corrective action primarily addressed bolt over base problems. We will leave that for another time. Excellent topic.

hundreds of builds. uncounted rebuilds.

 

[Koda]

good info about mags here. HB of CJ I wouldnt mind hearing about any old mag tricks if the subject should go down that path.

My current understanding talking around is that the Brownells contract USGI mag with the brown followers are outstandingly good. Confirmation? Respectfully.

my only experience with a Brownells AR15 mag is a cheapo 5 rounder I bought for range use and possibly hunting use. Its a metal mag that looks like a USGI except cut short of course with a plastic base that protrudes enough to insert/extract from the gun... The top portion of these magazines retain the finish & construction of their 20-round magazines & 30-round metal USGI magazines.... Its a piece of crap a jam-o-matic and usually in a big way. Im a newbie to ARs but this mag always jams my rifle badly.

 

[Arthur Chenoweth]

I had the same problem with a custom made AR10. The designer made the rifle for P-mags. So, I scraped some plastic from the lower edge of the latch window. Solved. Had to do it to every mag but it is quick and easy.

 

[dwaineshort]

2 brand new pmags wont seat.

the 2 bad ones are Gen M3 with overtravel stop. Other Pmags work fine but those are Gen M2 and dont have the overtravel stop. Other older Gen M3 with mag stops work, but now I am noticing they do fit tight... one of them requires a good push to seat but always does. I have one Gen M3 pmag with OT stop that works flawless.
The two new offenders are the worst though, sometimes if I really push really hard and wiggle it just right the two offenders will seat with the mag catch, no play, super tight. These are no-go for use...

I don't see anything noticeably different than the older ones that work except just the very few insertions are already leaving a mark and rounding the mags cutout upper edge in the mag, the others which have had many insertions and use show no abnormal signs of wear.

I checked my mag catch and the screw is threaded flush with the button face. Never had a problem until these 2 new mags.

Is it the mags, or the gun? anything I should look for, or try to see if the store will take them in return or exchange?

I dont think I will buy anymore Gen M3 pmags unless I find the problem. Any other brands to recommend? I have 1 DD mag that works flawless.

I had the same issue with my Troy lower I measured it. it was out of spec. my gen three pmags fit in all of my other AR-15's plus my tavor with no issues.