While I was in 3/5 Cav I was allowed to keep my own "personal" magazine supply and didn't have to worry much about their condition... But later in D 1/502d we had to turn our magazines in every time we came in from the field... though of course I always forgot to turn in those two new 30-r...

I don't automatically do it every time I load a magazine, but I sure tap them if I look and see a round that's not back where it's supposed to be. I remember whacking them on my steel pot... but I was in armor for awhile in Vietnam and remember whacking magazines against an APC, and that worked much...