About slinging. It's basic rotational dynamics. Need I say more? The sling has three parts. The pocket, the stay, and the trigger. The stay and the trigger are the two ropes attached to the pocket, and as you would imagine from the names, the stay is the rope you hold on to, and the trigger is the one that you release. Now WHEN you release it is the MAIN issue. To make things simple, imagine yourself throwing a baseball, and for this example, picture yourself watching yourself throw from the side. You wind up, your arm goes traces a circle over your head and your wrist snaps and releases at the top of your swing, at the top of the arc. But the ball doesn't go up, it goes forward... roughly 90 degrees from the place your released it. Now imagine that that same ball is on a tether. As you are swinging the ball in a circle, each moment of the ball's circular travel, it yearns to travel in a straight line... but at there is a competing force. At the same time the tether overpowers the ball's yearning and keeps the ball consistently turning around the circle. The tether pulls the ball towards the center of this circle where you are holding the tether. So when you release the tether, it loses all ability to overpower the ball's yearning to go forward. So at the moment you release the tether, the ball will get it's wish and travel in a straight line that is perpendicular (90 degrees) to the line formed by the tether at that moment. Slinging is the same way, when you release the trigger, the pocket opens and the ball will travel in a straight line from that moment on. See... simple rotational dynamics.Load it, Swing it, Release it.