From Descent-Community Wiki 1.1
Each time you perform an attack with a Bow, you may move up to 2 spaces either before declaring a target or after the attack resolves.
If you have Heavy Armor equipped, you may only move 1 space.
Each time you perform an attack with a Bow, you receive 2 movement points before or after the attack.
If you have Heavy Armor equipped, you receive only 1 movement point before or after the attack.
The change was made to clarify that the movement granted by this skill is be used directly before or after the attack and does not add movement points to the movement points pool gained from other sources (e.g. a move action).