Ricks Mini Carbide Cannon
Here are two pictures of Rick Comfort's Mini Carbide Cannon.
Here is the cannon caught in action at the moment of firing. Rick video taped the action and then used a Snappy to isolate this frame.
Here is the Mini with a 16F to give you an idea how small it is. The barrel is 4" long and Rick says it uses about 1/3 the Bangsite a 6F uses.