...rocks without a doubt, hands-down, the most dangerous thing you could possibly sling. One of the sling's major applications was in war. Not so good for killing finches at sixty yards, but fairly effective when wielded at some charging barbarians, or by the charging barbarians for that matter. Since that is not the application we're advocating here, below are some options for non-lethal
The most simple, ancient, and powerful throwing tool in the world… under 2 ounces
