Just curious here. . .Is there a need for concern if ammunition in PMAGs (or any other magazines for that matter) rattle? I tried to “settle” the ammos in the magazine by “whacking” it with my hand, but still it rattles around in there. 
Lots of magazines for lots of firearms do this, usually with every other round. Take one round out of the mag and see if it still rattles. I had a Springfield Scout that when you had an odd number of rounds in the mag, it would rattle louder than a drum line, even number and it would not make a noise.
Is this with the cover on? If so, take the cover off.
Cover’s off the magazine. I also did remove one cartridge and it still rattles, even with magazine in place on my rifle with full thirty count, and after chambering one.
Strange. I think I’ve only noticed this when I have the cover installed.
With a full 30 count, mine rattle a little, 29 doesn’t rattle at all.
Okay, I’ve tried it with the rest my PMags and even the USGIs. They all rattle. Could it be the ammuntion themselves? (Remington .223)
I allways wonderd about the rattleing too, i have 2 or 3 that do that.(with 30rds in it and no top cover on)But it never affected function.
That’s what I want to know. As long as the rattling is merely an insignificant nuisance that doesn’t affect performance, that’s fine with me. Hopefully it’s not a tell-tale of problems down the road. . .
Sounds like you may have some defective mags. Go ahead and sell them to me for a good price and I’ll do some in depth research on them. You can use the money to buy new ones. 
Don’t worry about it, unless noise discipline is a concern.
What is the mold date on thr PMAGS?
I’d highly recommend that you take each Pmag and load them out full and then liberally apply a can of expanding spray foam to the insides of each mag. This should clear up any rattle that you are experiencing.*
*I don’t really recommend this…
If I’m reading Magpul’s markings correctly on said magazines. . .Looks like it’s March and April 2008. Arrow pointing to the number “3” and “4” respectively with this showing 0↑8 .
Maybe it’s telling me to buy more PMags. . .
That’s the expiration date, need to discard them. I own a plastic recycling co.
EXPIRATION DATE!
I gotta remember that one.
That’s a good one! I used to work for a refuse disposal/recyclery (BFI). . . 
awesome