Folks worry way too much over something so simple. It's just a noise and it really only happens if you deliberately shake/rattle the magazine around in my experience.

The magazines in my SW40VE only rattle if I deliberately shake/rattle them in my hand. When loaded into the gun itself, the most noise they make is a dull "cla-clack" if the draw it from the holster quickly.
I've never had any of the magazines make any audible sound while secured inside of a pouch or even my pocket.

Folks are borderline obsessive and paranoid over the idea that something that the average passer-by would never even notice is somehow going to alert them that they're carrying a firearm.
Personally, I'm still waiting on the illusive fashion-savvy, serial cop-killing gang-banger to shoot me on sight for wearing 5.11 brand pants/belts, as the average paranoid guy on gun forums has repeatedly asserted is practically an inevitability.

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