This one is odd, even for me. I have a huge desire to build some siege machines just for target practice with something quite different. I'm thinking of items along the lines of trebuchet, ballista, catapult, and/or variations thereof such as a Roman Scorpion. I know these are not guns, but being powerful destructive tools they may have their own sets of laws. I don't intend to build anything massive either, everything I build will have a footprint small enough to fit in my pickup truck.