I recently received in a new batch of M&P AR’s. I tested them for fit with the PMAG and all is well! The PMAG’s drop free.
C4
I had a problem with the PMAGs failing to lock up in the MP-15s. Spoke with a guy from Smith on Wed who was at the department and they stated they were reworking the mag catch to eliminate this problem.
He also gave me a rough timeline on the MP45 (commander length) and 14 rnd 45 mags. 
I’ve only seen the older M&P15T models that won’t lock a PMAG in them.
I have had standard 15’s, 15A’s and T’s not lock the PMAG in.
C4
Clever. 
Any idea when (in terms of serial numbers) S&W made the fix? Maybe S&W isn’t saying, but if you’ve been checking the PMAG’s fit on the M&Ps passing through G&R, maybe you have an idea of the last no-go run?
Don’t know for sure at what serial number the issues stopped, but the 15A’s have a serial number in the 66XXX range and the 15T’s have a serial number in the 65XXX range.
If anyone that has a newer S&W (bought within the last month) can PM or e-mail their serial number, we can get close to when the fix happened.
C4
We have a few 15As here that we are doing a T&E on and they wont lock the PMAGs
Just checked the 3 S&Ws we have on the wall.
M&P15T s/n SW537XX (won’t lock with PMAG)
M&P15 w/Troy rear s/n SW577XX (won’t lock with PMAG)
M&P15 w/A4 carry handle s/n SW112XX (will lock with PMAG)
I haven’t tried a PMAG in my 588XX (July purchase), but I was under the impression that the issue was a tight magwell on the M&P 15. If a re-worked catch is the fix, I’ll be interested in knowing if it’s a plug’n’play retrofit.
SO…what’s the timeline on that compact MP45?
I was told 2008 for the compact and a month or two for the commander.
I’d be interested to hear more about when this change took place. I have a M&P15 with carry handle that I bought last November, SN SW072XX. I was considering buying some PMags but was hesitating. I had tried a friend’s “plastic” magazines marked “Made in Israel” and they would not lock up in my M&P. I didn’t want to buy 4 or 5 only to discover they wouldn’t fit in my Smith.
From what I can tell, M&P AR’s made within the last month are GTG.
C4
Is the problem with Pmags on the inhouse S&W models or did they included the Stag made ones as well?
Has anyone had any problems with the S&W and a Ceiner .22 kit? I finally tried mine out last week with a kit that runs 100% in my other gun and it refused to cycle at all. It would fail to eject on almost every round. It got sold today.
Standard M&P 15 with serial number 033XX locks all four PMAG’s I am using. This is an older model.
My experience has been that S&W warranty repair centers, which are often gunshops with excellent gunsmiths, have access to this type of info and will gladly share it. Of course, it is possible that ar clone repairs are being done only at the Smith factory.
Williejc
I’ve got the base M&P 15 purchased in spring of 06 with the CMT staked carrier. The first 4 PMAGS I had worked fine and the 4 I got after the exchange program work fine too. David
I saw on the MP forum there were postings of side by side pics of S&W magwells. The newer ones has a beveled edge on the front of the magwell. Does that have anything to do with the p-mag issue? Mine has the bevel, and it is sn# 51xxx. I ordered one p-mag to try for fit. I’ll pass the word about fit and function when I get it. Who knows, I may have a very lightly used p-mag for a karma give away by next week. Then again, if the S&W gods are smiling on me, perhaps I can order 10 p-mags from Mr. Gleason at 44mag.
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