I caught up with Todd Halter of Pennsville, New Jersey by phone after he finished a 24-hour shift at the fire station. He told me he and his father Jeryl started out building wooden boats together, and saw their first punt gun when they attended a waterfowl festival in Chestertown, Maryland.

They were intrigued enough to want one of their own. "About the only way to get a punt gun is to make one," Todd said. "We built the lock, stock, and barrel." Theirs is made of double-sleeved schedule 90 steam pipe, for safety reasons built much more stoutly than the often crude punt guns once used by market hunters. The Halter's gun has a two-inch bore and measures over 13 feet long, about 9 feet of which is barrel.

For a few years, the Halters gave demonstrations of their gun once a year at a waterfowl festival in Tuckerton, New Jersey, firing the gun with powder only. Then they met Knapp, who asked if they'd ever fired the gun with shot in it. They hadn't, until Knapp invited them to shoot it on his show.

Loading a punt gun isn't much different than loading a muzzleloading cannon. The Halter's takes 1600 grains of black powder, some wadding, and two pounds of lead BBs. Todd says the gun must be held at least at a 45 degree angle to load it.