Use these two charts to help you decide on which ammo works best with your slingshot and the situation. One chart gives you the weight and size of various slingshots. The other provides the energy available with the different ammo options. This info is especially important for hunters who use slingshots.
These charts are courtesy of the SlingshotCommunity forum - http://www.slingshotcommunity.com/threads/ammo-weight-and-energy-charts.815/