How To Make Rock Sling

While surfing http://surivalistboard.com , I came across a short youtube imbedded video demonstrating how to use an Apache Rock sling. The video showed a guy slinging it pretty acurately. It raised my curiousity. I clicked on a related video and found this demo on how to make one. Figured it was worth embedding here for future reference. I'm going to make one and start practicing. The instructor made a valid observation. If David could bring down Goliath with one well placed shot, a survivalist could bring down some game. Stay tuned for field observations.