Awesome find! Don't those large targets have a way of sounding like trash? I had 2 large cents that I could have sworn were pop tops. Congrats on digging it anyway, and even bigger congrats on your first silver dollar. Still waiting on mine!
I think if you beat it on the right mandrel, you could make a cap out of it, but I would save you the effort. Send it my way, and I will send you a collection of screw caps!!!