Put a sandbox inside, put the food bowl in the kitchen, and keep the cat in the house. That way there's no attractant and the coons will quit coming. At the very least, bring the food bowl inside during the night. End of problem. It's not exactly like hauling a 100-pound barbell.
But if ya just gotta play Harry the Hero, figure that at night and a moving target, a shotgun is your best bet. Sorta silly to set yourself up to where you think you need to do that, however.