Yes I see what you're saying. It was an optical illusion for me at start. The rim of the casing is resting on the finger and is in a vertical position. Judging from the length, which appears about one inch, it could be an empty large revolver casing, maybe a .44 Special or .45 Colt. It would be interesting if he would tell us what the headstamp is. But like you say, not of any great value.