Back in the paleolithic (mid-1970s) I brought a wrist-rocket style slingshot on a couple of hikes, looking to pass the time and have a bit of fun. It wasn't as much fun as I'd imagined. The ammo I could pick up off the ground wasn't aerodynamic enough to fly straight and darned if I was going to bring ball bearings with me as ammo. Too heavy, not to mention the dilemma of either leaving them littered around or else painstakingly tracking them down and picking them back up. So I stopped taking the slingshot with me.