I recently got into a manga called "Goblin Slayer", and was pleasantly surprised at the appearance of slings at one point--and a very faithful representation on top of that.
As the group of adventurers is cornered deep in a rubble-filled dungeon, a couple of slings are non-chalantly pulled out by the swordsman and dwarven mage of the group as opportunistic weapons as they hold hordes of goblins off while the rest of the group sets their plans in motion.
For those not familiar with Golbin Slayer, be warned that it is pretty graphic in all ways that word entails, so you might want to be careful where you read/watch it. That said, it is an excellent read.
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