Runite bolts (or rune bolts) are a type of crossbow ammo. They can be fired using a rune, dragon, dragon hunter, or Armadyl crossbow. Runite bolts provide +115 Ranged strength, making them the fourth strongest type of crossbow ammunition in the game, being surpassed by dragon bolts, onyx-tipped, and dragonstone-tipped rune bolts which provide +122, +120, and +117 respectively. Runite bolts are capable of hitting very high and are used more often during PVP situations or boss fights rather than general training, because of their high cost. They require a Ranged level of 61 to equip.
Runite bolts can be made by first smithing runite bolts (unf). This requires a Smithing level of 88 and a runite bar. Each bar will make 10 unfinished runite bolts and grant 75 Smithing experience. Attaching feathers to each bolt requires a Fletching level of 69, granting 10 Fletching experience per bolt.
Unlike all other runite equipment in the game, runite bolts do not use the shorthand 'rune' in their name.
For an exhaustive list of all known sources for this item, see here