I’ve had random issue of my 30rd PMAGs not locking the bolt open on the last round. I was chalking it up to possibly the WOLF ammo just not always providing enough gas pressure until last weekend.
I was at the range and the first mag of the day didn’t lock open, so I marked the mag. Went on to the next mag and it did lock open…same lot of wolf ammo. Then I loaded the first mag with some 5.56 and again it did not lock open.
When I got back to the table I compared this mag with the one that did lock open and the difference was immediately obvious…the follower was not coming up as far on the mag that did not lock open.
Didn’t see anything blocking the movement so I pulled them apart and found two different follower designs, one with a shallower channel for the follower stop.
Pics:
Left is the one that did not lock open, right is the one that did.
The mags that have the shallower stop channel do not always fail to lock the bolt open, but it happens often. When I got home I emptied all my mags and checked them. I have 12 standard 30rd PMAGs and one windowed. 6 of the standards and the windowed have this shallow channel follower.
All of the mags with the issue are marked M7 and M8, W2 for the windowed. The others are mostly M3 and M4, but there is one M8 that is OK. All of the mags appear to have been made in various months of 2009.
I’ve emailed MAGPUL but haven’t gotten a reply yet.
Just thought I would post my findings for any others who might be having problems PMAGs not locking the bolt open…may want to have a look at the follower.
I found one thread from last year with a similar comparison, but the posters issues were related to FTF malfunctions. None of these mags have caused any malfunction other than failing to lock the bolt open.
I was having this exact same problem with all 6 of my PMAG’s! I’d relegated them to range-only use and replaced them with L5’s, but now I’ll have to see if I can modify the followers. Nothing to lose, right?
Once I honestly posted a thread on TOS many years ago about how I knocked one off the top of my bed while playing with the wife. It fell about 5ft down onto our hard wood floor, and split down the back. They gave me two free mags no questions asked even though I broke it by knocking it off a bed post 5ft tall.
I am sure they will also want to take a look at them if they aren’t already aware of an issue.
Like it or not when you are dealing with high volume stuff made on machines things happen. I would just PM the guy Dozer on here. If you want a resolution contact the guys direct not some 800 number.
SSRacer,
Can you take a few shots of the magazine in the lower to see how much of the bolt catch engages the follower? We have seen issues with some bolt catches not being long enough to engage the follower. Thanks.
Apparently PMAGs have uses the rest of us must not be aware of. 5 foot drop is pretty impressive as well.
(Yeah, I know. Now back to the actual topic…)
I’ve beat the snot out of my 30s and 20s, never had a single issue like this - always locked back every time. Multiple purchases spread out over years. I’ll have to go back and compare them.
I am also interested in this bolt catch topic used with PMags. I have a well used rifle with well used PMags. Sometimes, the Pmags aren’t locking the bolt back. If I put the used PMags with a newer rifle, the bolt locks open fine. If I use GI Mags or new PMags in the well used rifle, the bolt locks back. It’s only when I use the well used rifle and well used PMags that the bolt fails to lock open. I notice a larger amount of fore/aft play in the bolt catch of the rifle. The mag followers are sometimes not catching the bolt catch and instead sliding past and then binding.
I’m guessing that in my situation, it is a combination of worn mags nad a worn rifle. Anyone else have this issue?
I own about 100 of the older Pmags. I’ve had several where the bolt catch slips off the follower, down in to the gap of the mag body, causing the same issue.
The issue is intermittent with these mags. Used all six of the standard mags with this follower today at the range and only had the bolt fail to lock back once.
Try installing a new bolt catch (Colt). I standardized on them in all my AR’s because they are usually correct length to catch the follower. Some other brands vary in size so much you can run into the issue. Not saying its guaranteed to work but there is quite a bit of geometry involved with how things are laid out and supposed to interact.
