Picked up 1000 pieces of once fired LC 556/223 brass on MeWe for $54 shipped. Grabbed a couple of handfuls, probably a 150 or so cases, from the bag without looking and ran them for 4 hours in my vibratory tumbler using crushed walnut with a little mineral spirits. Most came out as clean as you’d expect. The pictured few were the exceptions from that batch. The dark ones aren’t steel, just heavily tarnished. And only one bad case mouth in that batch. I figure these are range pickups from somewhere.