well after all that I think I probably led you folks down the wrong path, although it was an interesting journey. My shell had the pitch compound coming out of the fuse during the boiling process. I collected it all up and put it in a container and when it cooled it was a shiny black hard substance like plastic. It may have been a matrix for the bursting cavity, as I think the bottom cavity is probably full of balls. Case shot in other words.The shell is heavier than a standard 30lber even though it is shorter. I plan on diving today but this afternoon I will be back in the "lab" and will do some more investigating. Thanks for all the insightful comments, David