Cannonball
Smithing1 steel bar → 4 cannonballs for 25.6 Smithing XP (ammo mould). The wiki's optimal rate with a single mould is ~540 bars (2,160 balls, ~13,800 XP) an hour at the Prifddinas furnace; the double ammo mould (2 bars → 8 balls at the same speed) almost doubles that, and the ancient furnace (87 Sailing) halves the smelt time again, so set the bars/hr above to match your setup. Requires Smithing 35 + Dwarf Cannon.
Fill a target level to plan the whole grind, or leave it blank to use the hours above.
Smithing XP / hr13,824
Profit / hr125.3k
GP / XP+9.06
In 1 hour
Bars540
Smithing XP13,824
Profit125.3k
Materials
 Steel bar | 540 | 540 | -291.6k |
Produces (expected)
Value: 416,880
Rates are per hour; totals are for the basis above. Prices are live from the Grand Exchange.
Game data on this page comes from the OSRS Wiki: Cannonball, used under CC BY-NC-SA 3.0.