Feeding issues... 5.56mm overall length vs pmag

[jeepnuts]

Good evening ODT wise owls.

I took an AR to the range today and I had two brand new gen3 MCT pmags with me. I loaded them with some ammo I got from a member here that was in unopened packaging. Supposed to be contract overrun 5.56 (VUS headstamp) we’ll call it VUS herein.

The mags would not feed the rounds. The rounds were dragging tips in the mag and hanging up. Smack the mag a few times and usually they would pop up to the top but still not feeding. It would take the top round off but wouldn’t feed the second round because the round didn’t get lifted into the feed lips. The tips of the rounds were scratching the inside of the mag. I bought a box of magtech and it ran perfectly fine through both mags. Looking at the ammo you could see the VUS rounds were longer. I got a second opinion from a guy working there and he told me my mags were junk to throw them out.

I borrowed two mags from him. One was a DD 32 rounder that was well worn. Very very broken in mag and it ran the stuff fine. The other mag was a pretty new looking gen2 pmag (black) and it ran the stuff fine. I conceded and agreed it was probably the mags.

I got out the calipers when I got home and measured the rounds and I get an overall length of 2.2645 up to 2.2675” from the handful I measured. From what I understand they should be UNDER 2.2600” this would explain the rounds dragging in the mags.

Which is junk the pmags or the ammo?

 

[jeep78]

Try the ammo in some metal milspec mags.

 

[jeepnuts]

Ok here’s the deal... I was in communication with magpul and provided them with the same information i gave you guys. Magpul customer support says that their mags are designed to run SAAMI spec ammo. They say the ammo is out of spec and that’s the problem.

I don’t have any USGI mags but I had a brand new lancer mag and it also runs the ammo just fine. Even my other brand new gen 3 black pmags run it fine. Out of five different types of mags, The ONLY mags with the problem were the new gen 3 coyote pmags.

I took a needle file and removed a tiny bit of the material on the leading edge of the mag where the bullet tips drag and the coyote pmags run fine now. (We’re talking thousands of an inch tolerances) I basically just sanded down the mag a little on the inside.

I emailed magpul back and told them that I don’t take a dial caliper with me when i purchase ammo and I need mags that will run any ammo that I am able to find. If all the mags were jamming then I would understand. But, I don’t need 75 ten thousandths of an inch out of spec ammo shutting me down.

For me, I won’t be picking up any more pmags any time soon since I have a bunch of this ammo to shoot up.

YMMV
Tim

I think the lancer mag in the translucent fde flavor looks cooler anyway B)

 

[ReservoirDawg10]

You could measure the internal length of the mag. If under spec, I'm sure they would make it right.

 

[jeepnuts]

You could measure the internal length of the mag. If under spec, I'm sure they would make it right.

Little late for that, since I already opened them up. But, thanks for the suggestion.

 

[Radar363]

How often are you going to run across out of spec ammo?

 

[jeepnuts]

How often are you going to run across out of spec ammo?

No idea.

 

[Radar363]

No idea.

As far as I know I've never had any. I'm not sure I would rule out using a certain magazine on the off-chance I'll find out of spec ammo somewhere down the line.
I've never had any problems with factory ammo or ammo I have reloaded feeding in PMAGS, surplus GI metal mags, C products mags,Stoner mags or Troy mags, which is what my experience is limited to.

 

[jeepnuts]

As far as I know I've never had any. I'm not sure I would rule out using a certain magazine on the off-chance I'll find out of spec ammo somewhere down the line.
I've never had any problems with factory ammo or ammo I have reloaded feeding in PMAGS, surplus GI metal mags, C products mags,Stoner mags or Troy mags, which is what my experience is limited to.

I’m sure it’s rare. But, they’re the only ones that wouldn’t feed it. I fixed them for free. Now they will feed it. I just wanna shoot, ya know.

 

[Trouble]

Ur sposed to bang the mags on ur head first to get all the rounds to the back of the mag. Go watch full metal jacket