Smithing cannonballs (Grimstone Dungeon)

⚠ This profit comes from buying, processing, and reselling on the Grand Exchange. It assumes large GE volume and can be inflated or volatile — treat it as a theoretical ceiling.

With 87 Sailing cannonballs can be made at twice the speed using the Ancient Furnace in the Grimstone Dungeon. Isles nearby can unnote bars to make cannonballs at a cost of 100 coins per bar.