You had me wondering for a minute, I hadn't noticed any noise from the magazines, but I happened to have 6 fully loaded 40 cal mags close at hand, 4 made no noise at all, 1 made a very slight noise, and 1 rattles pretty good, I don't know what it is, but it should be fixable, find out what's rattling and fix it, the magazine does come apart so you might look and see if you can figure out what's happening to your mags.