Mad slingshot genius Joerg Sprave has accomplished many things in his years of DIY weapons engineering. A rifled slingshot that shoots knives, an air-powered bazooka, a slingshot with an internal magazine, and a Coke bottle gatling gun to name but a few. But his latest invention is perhaps the most impressive, but in terms of engineering and raw firepower. Say hello to the fully-automatic slingshot crossbow.