I have feeding and lock back issues. When I change to my 30 rounder I have no problems. Can I stretch the spring to get a little more force or should I replace the spring entirety?
Replace the spring never stretch it.
How many rounds do you have through the mag?
About 30 or 40.
Drop Magpul and email, they’re usually good at taking care of issues.
what kind of ammo,gun, lpk are in play here. the mag may not be the issue. i had a bunch of failures to lock back on 2 fresh out of the package pmag m2/30. my lancer awm and pmag m3/30 worked just fine. turns out it was ammo related. if you shoot notoriously under powered ammo(steel, pmc, etc) this may be your issue, espicially if youre shooting a midlength. there are many variables.
My gun shoots flawlessly when I’m using my pmag 30 and has trouble on the 20. Several times I’ve swapped back and forth and the same. It doesn’t always happen but usually after about 3-5 rounds through the 20. The 20 barely locks back when it does and I can pull my bolt back then have to press my bolt catch to fully engage it. Seems like a weak spring to me.
It’s not magpul they don’t make 15 round magazines. It’s been modified by someone else.
Here in Cali we get after market 10/30 round magazines. It has a limiter inside and is then permanetly sealed to comply w/ CA laws. Dependability is usually based on who does the mod.
When I lived in Cali the 10/20 pmags were known to perform much better than the 10/30.
A Jersey mag?
It’s a 20. I had a brain fart.
You have just the one I assume?
I have had this issue with all my pmags. I had to cut a coil off of the bolt catch spring and worked fine then. I eventually upgraded the springs to extra power chrome silicon springs with no issues now. Happened with both 20 and 30 mags. Used stag LPK by the way, dont know if they make their springs stiffer than others.
Correct.
I had been using PMAG 30’s with absolutely no problems in my AR. I then bought 5 PMAG 20’s (middle of 2012) and had the same problems described by the OP with all of them. I finally got all five 20rd mags to work very well.
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I smoothed all internal seams and lightly sanded the internal surfaces of the magazine shells with 400grit wet-or-dry sandpaper. I then applied a little paste wax to the interiors of the magazine shells. This smoothed out the action and all feeding problems were gone.
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I found that there was a little too much projection at the rear of the top of the magazines. This extended material on the back of the magazine was providing friction on the front edge of the bolt catch. Trimming about .015" off the back of the magazine (just to the right of the “U” at the rear of the magazine) with a file is all that was required to have perfect bolt latching every time the last round was fired.
If you do some reading you will see that this is quite common with the PMAG 20. It’s been talked about here and elsewhere.
That’s a rather interesting first post. Lacking personal familiarity with their 20 round magazines it would be interesting to see if others beyond the two of you are having the same issue.
Welcome aboard by the way.
Edit: Seems IG was able to clarify yet another issue. But speaking of, have they addressed this? And would you endorse what SkipD did to remedy?
I found one of the older threads and it seems like the most common solution was to just trash the old mag and buy a newer one with the better follower. I don’t know what Magpuls response to this has been but I think they should make it right. The mag was fairly cheap I bought it last year but I’m not going to go screwing with it a great deal and either make it worse or void the warranty. I’m going to see what they’ll do about it.
If it’s this bad of a problem it seems like they’d work with you.
Part of my problem (failure to lock the bolt back) was, according to the folks at Magpul, probably due to a minor dimensional difference in my lower (Fulton Armory). The five magazines that I have are from late 2011 production and they said that there weren’t any changes made to then-current production as compared to mine. My magazines all have then-current (early summer of 2012) springs, followers, and shells.
Since I’m capable, I found it much easier to troubleshoot and repair the five magazines I already had than to swap them out. All five magazines work as expected today. The action of the followers is extremely smooth, feeding is perfect every time, and the bolt locks back on empty magazines every time.
Is it a Gen3 Pmag 20?
I have had zero issues with my M3 PMag 20. I also have an original Pmag 20 as well, and I could see how those could have problems.