No idea - the piece is about 4" long. I always hoped it was from the Dictator or some other 13" mortar because I bought it when I was a kid at the old now-defunct Fort He ll Museum at Petersburg.
The bigger they get, the more difficult they get to move (or transport)-even on concrete. I have a 15" ball that was removed from a swamp by putting it in a 55 gallon drum and rolling the drum out over the muck.