Mithril bolts

Ironman verdict

At least 7 monsters drop it. The easiest is Chaos druid (level 32, 4/128); the best rate is Skeletal Wyvern (level 109), at 5/128, about one per kill. You can also make it yourself: it takes 33 Fletching and gives 50 Fletching XP, using 10 × Mithril bolts (unf) and 10 × Feather. There are 2 other recipes below. Other sources include Gnome Restaurant. Making ten takes 100 × Mithril bolts (unf) and 100 × Feather and gives 500 Fletching XP. Reaching level 33 Fletching takes 18,247 XP in total; the Fletching calculator counts the actions and materials to any target, and the Fletching guide has the Ironman training route. 3 recipes use Mithril bolts, including Emerald bolts, Mithril grapple (unf) and Sapphire bolts. It is worn in the ammunition slot at tier 30 as ranged gear; compare it with every other piece on the Ammunition list. Mithril bolts is available on free-to-play worlds too. It is tradeable on normal accounts, but an Ironman cannot use the Grand Exchange or trade for it, so the sources on this page are the whole list. High Alchemy turns one into 12 coins, which is 8 less than the shop price, so buying it to alch does not pay.