Although I have had my Ace 250 for over a year now, I really got to use it quite a bit on vacation last week at a beach. Now that I am hooked, I will be going every chance I get! Anyways, on vacation I found quite a bit of bullet caseings and I am wondering if they are copper and worth keeping? I also found a 1947 what penny and a 1942 indian head nickel. Are these considered good finds? I see a lot of people keep pull tabs and bottle caps. Are these worth anything, or just to show?