Always enjoy reading finds on different forums, but never got into it heavy. Used one for work to find evidence, and my dive team has underwater Fischer .

We used a very basic White for finding spent casings etc. Then Garret produced a "CSI" model that discriminates different casings somehow. Its actually one of their higher end commercial units, that they put a different menu on- rather than settings to discriminate out tin, aluminum, whatever, it has has calibers.

It has been useful.