I was hunting and old park today, moderate trash, black soil (some coal). Hunting in IM 12 conductive fast deep off. I had three coins that bounced from the iron side of the screen to the silver dimeish position. Two of them were wheats the other a 43 merc, flat on its back, at only about FOUR inches! The signals sounded like crap and I dug them only because I had the day off and wanted to experiment with my settings and see what would happen. After I dug the merc I checked the hole and there was no other target. I have NEVER had a shallow silver coin sound like this before. Has anyone else ever had this happen?