bq. Our 25 Inch Field Cannon is our loudest carbide cannon! This cannon features an automatic charger mechanism for rapid, multiple firing plus an automatic flint ignitor. Weighing 7 lbs, it operates on the same principle as a gas engine in an automobile—using gas, fresh air, and a spark. Powdered calcium carbide “ammo” is added to the water in the chamber of the cannon. The auto flint firing mechanism creates the spark to give perfect combustion. This 25” cannon produces a realistic flash and boom that makes celebrating a real bang-up time. Adult supervision for children under 16 is recommended.