MILITATED

Just another update: After the modification, the PMag fits perfectly into the G&G Raider every time without any problems - absolutely no wobble either, which is better than most of my standard mags. As for my Blackwater, I probably have to modify the mag a little bit more (it catches after applying force, so I guess it just needs that extra bit of space to catch normally). But yeah, those three little teeth things and the height of the mag catch hole were the problem.

Right so I've made a bit of progress it seems. I didn't have a dremel or anything around (all in the shed) so I decided to use a box cutter as a replacement. Instead of dremeling, I just sunk the blade into the polymer which I wanted to remove. There were three tiny teeth sort of things in the mag catch hole on the pmag. I removed all three of those, and slightly increased the height of the hole by about 1mm (probably just under) by rubbing the blade in a line along the polymer. Gotta make do with what you got, right? Anyway, after doing that and being amazed at how clean it turned out, I popped the mag in. Now it didn't catch properly, but I pushed the mag release thing (not the button, the bit on the other side) down (as if I was trying to push the latch into the hole of the magazine). Well, that seemed to work and the mag isn't coming out I will increase the height of the hole by like a quarter of a millimetre (hopefully) and see if that just allows the mag to slide in without me having to push that mag release bit. That probably made no sense and was poorly described, but I will try provide pictures once done. Yeah that seemed to work, although it won't just go in like a normal mag, you have to slap it in as Qlimax suggested. I just had to modify mine first.

Was hoping for this to be a fix for me, but you can smack this mag as hard as you want and it won't catch. Not sure why

Might be worth noting that they worked with a Masada ACR. Part of the mag had to be modified but not a part which would effect it in an M4 - unmodified ones also have the same problem.

Got no idea, bought them off a mate after they were found in a box. He can't remember either, and they've got no indication as to what company made them.

Bit weird... Just stuck a bit of electrical tape under that hole and it holds the mag in better. Dunno how it will feed though. Will try it after. Update: BBs don't feed either, but feed from other mags. Maybe they're just not meant to be

From measuring the holes in the mag where it catches, I noticed that the PMags hole is 1mm smaller in terms of their height if that makes sense. Could that possibly be the issue?

King Arms Blackwater BW15 Carbine. Tried it in one of my friend's G&G Raider and it does the same thing. Other mags work fine though.

I've recently bought a few PMags, but I am having a slight problem with them. They will not lock into the magwell; they just don't seem to catch. I've tried them in two different guns (one of which I have seen PMags in before), but they have the same issue. Standard magazines fit just fine and lock in on both guns, so why won't these? You can literally just pull the mag with very little force and it just comes out.