Coke bottle

balloon

sosatie sticks with balls (pom poms/polystyrene) on the end

Cut the coke bottle at the top.  Keep the part with the lid.  Push the balloon through the opening (lid) and fold over the lip.  Put ball/pom-pom on end of sosatie stick.  To shoot:  Place sosatie stick in balloon and pull back.  Release both balloon and stick to shoot.