The Arms & Equipment in the Civil War Message Board

8" Artillery at Vicksburg

I have a piece of 8" round shot that was dug at Vicksburg many years ago. I don't know a lot about artillery, but from what I've read 8" exploding round shot could be from a mortar, columbiad or smoothbore Dahlgren. The piece is 1.5" thick. Does anyone know if all these types of 8" guns were used at Vicksburg, both sides or not? Is there a way to determine what type of gun it was made for such as the thickness of the wall?