Great find there! He's right about watching how fast you start popping them now. I dug my first half dollar a year or two ago and a friend said watch how fast they come. Sure enough, over that summer I dug like 4 or 5. A barber, a few walkers, a Franklin, and maybe one other but can't remember off hand. Prior to that, the only halfs I ever dug were a 2 or 3 clad Kennedys, but...I had dug a Peace Dollar in the past. Never expected that one, as it was right near the surface.
On copper or bronze coins after you've washed them you can dip your fingers in olive oil and rub it onto the coin. It will not only bring out details that you can't easily see, but it will also protect the coin from further degradation due to the air oxidating the coin over time. This is more critical when the coin is first dug, as I've seen them degrade right before my eyes (well, almost...but in minutes at least) after they've been dug. For that reason some people put their copper or bronze coins in a small container of soap and water right away when they dig them, to soak and break up the junk on them. Then when they get home they take them from that, wipe them dry, and then immediately put the olive oil on them. This is popular among some relic hunters as well with old buttons and other relics. If you do coat the coin with olive oil, be sure to also coat the edges of the coin so no air can get to them through the sides as well.
Can I ask what VDI # it rang for you? There are at least three or possibly four (have to look at my chart to refresh my memory) areas on the conductivity scale where Indians can fall. There are even certain Indians (I think fatties, but I've never dug one) that read well down into the pull tab range. For sure anyway, not all Indians will read like a wheat penny, as they changed the copper/bronze/whatever makeup of Indians at least 3 or 4 times if not 5 over the years.