My grandfather grew up in West Virginia during the Depression and he and his brothers used to make their own slingshots and hunt squirrel, grouse, and other small game to help feed the family. When I was a kid I saved my money and bought one of those new "wrist rocket" slingshots with the surgical tubing bands. I showed it to him one day and it only took my grandfather a few times to get the hang of it, and after that he could knock soda cans off of a fence post at 25 yards pretty consistently. He was not as good as the guy in the video but I can tell you I wouldn't want to be on the receiving end when he had that slingshot loaded with a marble!