http://youtu.be/R6QlVhKVwZw A lot of people have problems with nails this is a pretty good way to get rid of most of them . As you know targets give different responses when scanned two different ways when there not round or square if a target is long one way and short the other way it will read different period . This also go's for depth reading as you can see in the video . to confirm this try pinpointing a long target the pinpoint will move from where you get the best hit . Caps come in all different metals some have aluminum foil in the cap others are not round some ragged and others half there. Caps will high tone on you if they have points on them watch the video and see what caps can do .Any ? just ask I will try to help. This will also be posted in the hunting in trash video. sube