>>3084646>rubberWithout access to heavy industry, rubber is actually quite rare. Before natural rubber was heavily cultivated in the days following the start of the Industrial Revolution is was exceedingly rare, and anyone looking to treat the rubber to possess the elasticity needed for a real slingshot would have had a hard time doing it without a modern chemical industry behind them. Slingshots-as-common-weapons simply wasn't possible until cheap, synthetic rubbers came around, and if ANY were made before then they would have been extremely labor and materials intensive.