I have no idea of where you looked, John, but Ripley shows the Mordecai sheet, Figure XII-8, for fixed ammo, so you have THE SOURCE right there on page 260, labeled: Canister, 12 pdr. Gun which is completely different from 12 pdr. Howitzer, as you know. The only discrepancy that I find between these two sources is a very minor one. Ripley has the O.D. at 4.52 and Dickey has it as 4.5. Are we really going to argue over 20 thousandths of an inch. I think not.
Tracy