I have been using my bounty hunter lone star for about 2 months now.Each time I go out for a hunt what the reading says and what comes out of the ground are never the same.Cans read iron,gold to a high pich silver.I found bullet casings reading iron to 5c.My question is...is this normal or is my MD messed up and am I missing the good stuff?I set the sensitivity to 3/4 or 3 o clock and dis to 1/4 or 9-10 o clock.most of the time on all medal or coin shoot mode.