Reply To: Unknown metal › Forums › General Discussion › Unknown metal › Reply To: Unknown metal July 21, 2016 at 7:27 pm #2775 Alan BalmerKeymaster @alanbalmer Interesting. Herculoid or Hercules Powder is (was?) a trade name for nitrocellulose. Is it possible the bag originally contained something else? When I was a kid, my Dad had a couple reels of nitrocellulose movie film. That stuff was fun!