9. Turn a Pen into a Gun
Do you have an ink pen, some tape and a piece of cardboard? If so, you can create a surprisingly powerful gun. This won’t kill anyone, but it is an ingenious prepper project that will have enough force to knock things over. After the SHTF, you may be able to modify this to successfully shoot very tiny animals. It could also be used as a last ditch defense method if you shoot someone in the eye or knock something over from a distance as a diversionary tactic.