Will,
Thanks for the reply. I'm not at all worried about projectile speed and fouling since I'm only going to be firing blank shots.
I'm a cast member at the South Florida Renaissance Festival and play King Henry's cannoneer (aka "The Cannon Guy"). My job is to fire the cannon for opening, closing and any other time the need arises. During the 26 days the Faire runs, I figure that between the howitzer, handgonne and various other BP weapons, I'll probably burn through at least 4 pounds of powder. Cool job huh? :-D
Never having used Elephant BP, I just wanted to be sure I was going to get a good boom every time I touch off the cannon.