A sling is a weapon used to fire rocks farther and harder than could be thrown by hand alone. I made this sling from bark fiber that I made into cord. The cord was then tied in such a way to produce an area in the middle with three cords. A strip of the same bark fiber was woven between these to form a pouch. A loop was tied at one end of the sling and a knot tied in the other.
To use it, the loop is slipped over the finger and the knot is held down with the thumb. A stone is placed in the pouch and the sling swung over head. At the appropriate time the sling is swung forward in a throwing action and the knot held in the hand is let go. This causes the pouch to open and the stone to fly (hopefully) towards the target.
I hadn't used a sling for eight years but the first target I set up and filmed, a potsherd on a stick at 10 m, was hit first go! Next I set up a log at 20 m and required more practice. Targets of potsherds and tiles at 10 m were set up in a clearing. Tiles on sticks at 15 m were set up in a stretch of creek. The last shots are back in the clearing at 10 m.
Learning to use the sling is difficult and practice is necessary. When aiming line up the swinging plane of the sling with the target to determine Y-axis aspect and use release timing to determine x-axis aspect. With timing (right handed) too early and the stone will got to the right, too late and it will go left. Practice to make it go at the right time. Use larger stones as they swing slower and are easier to time. Use smooth stones so they fly straight and don't cling to the pouch when released.
The advantage of the sling is that it's easy to make, portable and the ammunition (stones) are every where. The disadvantages are it's difficult to learn to use accurately, noise and movement give it away when used, it can't penetrate a target like an arrow (unless using some king of weighted dart) and it can't be fired in thick forest. Interestingly, the sling has a range comparable to a bow. From my research, the record for the longest sling shot was 505 m and that of the bow just under 500 m.