Bennie managed to snap this photo when a member of the Cannon Society fired this half-pounder cannon. I'm surprised not to see the cannonball floating in mid air! :)
Some time ago cannons fell under the Firearms Act, which meant that they were governed by the same restrictions applying to modern firearms. The Cannon Society petitioned the authorities, and to satisfy the South African Police they drew up an official safety handbook, set up a code of conduct, and agreed to training courses for gunners. Today cannons and antique muzzle-loaded firearms have been deregulated and no longer fall under the Firearms Act (although a competency certificate obtained through proper training is required).