Got me some Magpul Pmag aggravation

[Big Bad]

Recently looked at a Diemaco AR, beautiful weapon, top of the line build, and then of course there's the barrel. I've always coveted one.

Of course it functions well, however it does not like my supply of Pmags. Specifically, it works well with newer Pmags and metal magazines but I have 8 Pmag 5-30s that I managed to obtain in the aftermath of the Sandy Hook panic buying, a beautiful green colour they are, but in this rifle they are slightly hard to insert and because of the friction do not drop out as they should when playing 3 gun and the ejector button is pushed. More seriously, the rifle's bolt does not reliably remain open when one of these mags has been emptied of its 5 rounds, that is a killer situation since you can't tell you're out. I'm pretty sure that failure is because of the mags, I've had such magazine problems before in other semiautos.

If I'm reading the code on them correctly, these 'sticky' mags were made on 12 May, 2010, if that means anything. The Pmags that work in the rifle are all labelled Gen 2.


What I'm looking for is opinions on whether or not it will pay to (gently and carefully) grind down the outer plastic of the offending mags so they will insert and come out as per normal, and if I do that whether it might also cure the bolt issue. These green Pmags do work well in other ARs BTW, it seems to be strictly a Colt Canada issue with them. What I'm really hoping to hear is that someone else has had the problem and solved it....

 

[*MALICE*]

Just to double check: the rivet is not binding on the inside of the mag well, is it?

On the original run of Gen 3 pmags, some had some flash on the inside of the mag body. it would cause the follower to move forward a skootch when it reached the top of the mag. If yours has that flash, a razor blade to scrape it away should solve the problem.

If that's not the case, then your mag well or bolt stop slot could be out of spec.........although with a Colt it's less likely (although not impossible).

I had the same issue with Gen 3 pmags in my lower. Gen 2 pmags, LAR pistol mags, aluminum GI mags; they all worked fine. Rather than avoid Gen 3 mags, I just welded a small bit of material onto the tip of the bolt stop finger to make it about .02" longer, and now I have no more problems.

Some people use a modified 9mm bolt stop to rectify the issue, but the 9mm bolt stops aren't ramped on the front so the lugs have a tendency to smash into the bolt stop (the ramps are there so the bolt stop gets pushed down as the lugs slide over top of it) and then your bolt locks open on the carrier, or it closes with no round in the chamber and you have the same issue you have now.

 

[jory]

Check the inside of the magwell to make sure the rivet in the mag isn't getting hung up on it. I had that happen with a few of my PMAGs- a quick pass over the rivet with the file on my leatherman fixed that.

 

[Sinasta]

Mags are disposable items. They've lasted 8+years now. Toss them in the range bag and buy newer Gen 3 mags.

 

[Big Bad]

Check the inside of the magwell to make sure the rivet in the mag isn't getting hung up on it. I had that happen with a few of my PMAGs- a quick pass over the rivet with the file on my leatherman fixed that.

I did look at that but maybe not closely enough. I did decide to get the rifle so I'll check again.

Mags are disposable items. They've lasted 8+years now. Toss them in the range bag and buy newer Gen 3 mags.

Yeah but I paid a premium price for the things, not that Canadians don't always but there was a big shortage on at the time. I'll try reducing one with a coarse stone to see if that fixes the problem. Waiting for the government's blessing on the purchase.

 

[Big Bad]

Just to double check: the rivet is not binding on the inside of the mag well, is it?

On the original run of Gen 3 pmags, some had some flash on the inside of the mag body. it would cause the follower to move forward a skootch when it reached the top of the mag. If yours has that flash, a razor blade to scrape it away should solve the problem.

If that's not the case, then your mag well or bolt stop slot could be out of spec.........although with a Colt it's less likely (although not impossible).

I had the same issue with Gen 3 pmags in my lower. Gen 2 pmags, LAR pistol mags, aluminum GI mags; they all worked fine. Rather than avoid Gen 3 mags, I just welded a small bit of material onto the tip of the bolt stop finger to make it about .02" longer, and now I have no more problems.

Some people use a modified 9mm bolt stop to rectify the issue, but the 9mm bolt stops aren't ramped on the front so the lugs have a tendency to smash into the bolt stop (the ramps are there so the bolt stop gets pushed down as the lugs slide over top of it) and then your bolt locks open on the carrier, or it closes with no round in the chamber and you have the same issue you have now.

Thanks for that information. Since I know Gen 2 work in the thang, that's what I'll buy if I have to. Going to have to do some research on Pmag generations, seems to be more of a big deal than I would have thought.

 

[Trinimon]

See if they fall free when the rivet is outside the magwell. Look carefully at the rivet and see if it is making contact with the magwell. Hit it with a file. Don't remove too much material or you will end up removing your rivet entirely and will have to rivet them again.

Heck, if you have a rivet gun, just remove the current one, function check it to see if it falls free and if the bolt locks back. If so, rivet them with counter sink rivets.