The sling was used for warfare and for hunting from antiquity, up to very modern times (my father was taught to use one as a boy).
Famously used by David against Goliath, the Romans and all of medieval Europe.
This medieval sling is based on a fairly normal construction type of a veg tan leather pocket with slits allowing it to be moulded slightly and comes with waxed cords and a finger loop. The cords are 36"/90cm long.
You can see a demonstration of how to use it here.