I've owned enough to know it is normal, but what actually causes it? And new mag springs or not, when I unload a mag by hand at least one round will rotate a bit it the mag. Never been an issue with function. On my 6906 which is almost unfired, I can load 7 rounds until the rounds start to rattle

I figure with the experts on here (and I'm a neophyte at best when it comes to gunsmithing. Aside from removing he firing pin and cleaning the channel I've never detail stripped a 3rd gen) somebody must know.

It's just the way the rounds sit at the bottom when it's fully loaded. I've had the same thing happen to me with many Glock, XD/M, CZ, Sig, etc double stack magazines. At least it goes away when the mag is inserted into the gun unlike the XD and Glock mags where it happens after it's in the gun.

You can usually take some rounds out or push down on the top round with some magazines and it stops. Some just do it no matter what.

Mainly caused in 9mm where the rounds are tapered, allows the noses to bounce up and down.

I've also had it happen to quite a few 45acp mags and only in double stack magazines. Most of the time the entire round with case can rattle back and forth after being fully loaded.

I've mostly had it happen with double stack 9s,
It used to bug me
I resigned myself to accept that which i cannot change.

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