The Tavern

While exploring, characters with this feature passively increase stack quantity for arrows and bolts if present in inventory. Maybe also for sling stones, though sling/rock compatibility makes this questionable.

Suggested as a racial feature for deep elves and other species meant to have an affinity for launchers but low in strength, as low strength means a need to fire more missiles to secure a kill and a lower threshold for the strength of monsters they can fight in melee, compounding to necessitate more frequent mulching and a greater risk of game loss due to insufficient ammo generation. Flavor aside, this might also be a nice perk to randomly receive as a good mutation, though I'm much less confident about that.

Alternately, this feature could be provided through a scarf flavored as a magic quiver. Would be a great fit as a starting item for arcane marksman.

Admittedly, this feature would be less important if mulch chance scaled with strength, but tuning that seems more difficult. Furthermore, the fletchery approach seems more strategically interesting, as it's an effect players could opt into (or adapt to, if acquired randomly).

Lack of ammo is the main reason I don't use ranged weapons.

Interesting. I use ranged weapons in most my games and there seems to be plenty of ammo in the game.

I've found that the relevance of ammo varies severely depending on background, species, weapon type, and god. If you want a truly miserable experience, try playing a deep elf arcane marksman who worships a god other than Okawaru... although, I admit this isn't quite as bad now that weapons aren't randomly cursed, as you might get lucky and find an early +2 dagger of venom or something that'll let you kill more things without using ammo.