Get a cereal box and cut a piece about the same size as the screen and then tape it to your AT Pro. Dig all repeatable targets.
I have dug six Indians with the AT Pro. None of which I could of said "hey I think it's gonna be an Indian". Mostly I probably just hoped it wasn't trash and gave enough of a high tone to warrant digging. If I was going by numbers I would of NEVER dug them. If you want to find some good stuff, especially the stuff missed by others, you have to learn to use your ears.