Slingshot Crossbow Pistol (homemade)

VERSION 3: VERSION 2: I built this in the first place to have a projekt to test my new router. I measured the speed of the arrow with a chrony and it makes it to 7,14 joule (125fps; 10g projectile). It is more a toy than a weapon I think. But still funny :) assaulting a foam target and the ground o.O