It’s like my grand dad always said: never bring a single barrel spud gun when only a double barrel will do. If you’re in need of the double barrel goodness, this build guide can help.
The old standby in spud gun design is a simple chamber with a flammable gas inside and a basic ignition system. JC, of JCOPRO.net, mixed thing up a bit by both changing out the propellant system from an explosive gas to a pneumatic system and by introducing a second barrel. The result is a sweet spud gun that fired two projectiles independently from a primary chamber.
Watch the video above to see him testing it out with a water payload and then hit up the link below to see his schematics and build one for yourself.