My powder chamber holds about 25 grs. of FFG.  The first shot was a double charge and take cover.  The Ball went about 150 yards.  Mortar survived.
After that  I was just pouring powder in from the measure and filling the chamber.  As long as I kept all the powder in the chamber I got a about 30 yards.  Any powder in the ball cone and the range was drastically increased.  This was an exercise to see if I had built the mortar right.   I used up all my FFG this evening
I had a bag of Salvation Army  golf balls and when I to Winchester I realized  i had left them on my desk, so I whip into K-Mart and bought the cheapest dozen I could find.
Playing with Windows Movie Maker tonight  I learned how to move one frame at a time and cut out the garbage and add sound. It's surprising how that fireball is only in one frame.