How to Build a 3″ mortar Cannon out of and old fire extinguisher.
DO NOT TRY THIS AT HOME!
I have been Engineering for 20+ years and Building Guns for 15+ years. The Inner core is very important, unless you are competent with understanding explosive pressures and metal schedules etc. Building guns of any sort is very dangerousand not for the inexperienced. You have been warned!
Joint project with my friend Gary (he did the welding).