Arrows shot from a bow enchanted with Knockback will deal increased knockback when hitting a mob, consistent with the behavior for Punch. This behavior does not exist in 1.20.6 and below.

At the same time, non-arrow projectiles (snowballs, tridents) that have been enchanted with either Knockback or Punch do not have knockback applied to ranged attacks; however, Knockback is still applied to melee attacks.

This behavior extends to the minecraft:knockback data-based enchantment effect. The bug likely stems from a bow-specific implementation of Punch that has not been migrated fully to the 1.21 data-driven approach. As of 1.21pre3, there is no way to modify the knockback of a non-arrow projectile through enchantments.

Expected outcome: Knockback should not be applied to arrows shot from a bow enchanted with Knockback.

Observed outcome: Knockback is applied to arrows shot from a bow enchanted with Knockback, but not to any non-arrow projectiles.

Steps to reproduce:

1. Run the following commands:
   /give @p minecraft:bow[minecraft:enchantments=\{levels:{'minecraft:punch':2}}]
   /give @p minecraft:bow[minecraft:enchantments=\{levels:{'minecraft:knockback':2}}]
2. Fire an arrow each from both bows; if the bug is present, both arrows will deal similar knockback