This is the main body of an attempt at designing a Gyrojet Mark 1. This needs testing but it is as close as I can estimate and should be easy to fine tune. You will also need the vents, in a separate file. Paint the inside with titanium white paint to insulate from heat. The inside will need a hollow cylinder of rocket fuel, with a central tunnel for internal burn surface area. Do not overfill, you need the space to screw the item shut. Screw shut firmly. The body and vents screw together. The rotation of turn in flight and the threads are in opposite directions so that the motion of flight will tighten rather tan loosen the threads and they will remain secure. The outside of the vents has the space for a large pistol primer to be inserted. remember to paint inside surface of vents as well. With inner surfaces painted, fuel inserted, threads and body assembled, let dry, insert primer, then fire. Use responsibly and at your own risk. This is not yet tested and needs testing.