Buy RS3 Masterwork bow
The Masterwork bow is a tier 99 bow in RuneScape 3 with tier 100 damage and accuracy. You need level 99 Ranged to wield it. It is a members item that uses arrows and has an attack range of 9. It hits hard with 1275 ability damage and 3100 accuracy.
The bow has a passive effect called Masterworked Mending. It heals you for 2% of the damage you deal. This works on basic attacks, abilities, bleeds, and burns. The heal has no cap. If a hit goes over the 30,000 damage cap, the heal still counts the full damage before the cap.
Making this bow yourself is a long job. It takes level 110 Fletching, level 110 Woodcutting, level 99 Smithing, and high levels in other skills. It also needs rare materials and about 3.5 hours of work. Buying one skips all of that.
The bow degrades over 100,000 charges. A full repair costs at most 800,000 coins, and the cost drops if the bow still has charge left. The Masterwork bow is a strong pick for any high level ranger who wants big damage and free healing in every fight.