If you're like me, you look at your pile of 248 bazillion hard to come by (ahem) 9mm brass and wonder if that will be enough. You hate to toss any brass into the scrap heap knowing it's just so difficult to obtain. (ahem)
I get a fair amount of my brass from the local range, which is covered with pea gravel. Pea gravel likes to hide out in 9mm brass. Sometimes it doesn't come out. I have found that if I invert the brass, rotate it in my fingers while pinching it lightly with my Leatherman pliers, those rocks will fall out most all the time.