I have several small cannons. One is an original signal cannon built about 1800-1820 and has a 1" bore. I have fired many times on holidays and it makes quite a bang. Another is from South Bend (Barney's Cannons back when my wife bought it for me.), it also has been shot many times on holidays. When we lived in Indiana kids would come to the house on the 4th of July every year and ask me to shoot the cannon. With about 100 to 120 gr. of bp it makes a significant bang.