A lot of farmers have them on a timer. Every so often they fire off a few rounds...just loud noise. It is for the watermellon patches to keep the birds and other animals from destroying the crop.
Yup, propane powered potato cannon. �The ignition source is a buzz coil built with a Willys coil, a Chevy condensor, and a Bosch 8 pin relay. Fun to build and more fun to shoot.