Learning to use the All Metal Mode takes some time. I suggest you start in a low trash area otherwise you will be overwhelmed in no time. Remember the iron target are wider with bleeding edges from the halos. You want to look for the targets with crisp edges. When your ears get tired, switch to DISC 1 and you can still get decent depth. If you are still getting too much trash, turn up the iron discrimination a little more. Another option when in All Metal is to turn the threshold down to zero of even into the negative numbers to save your ears. Really helps and still gives good depth. I think you'll find out if your ears get tired you will not get nearly as much. After some conditioning you can go longer at full throttle. Also in DISC if you get a scratchy target, flip to All Metal and it will be a lot cleaner.