Why does my powershot valor consume ammo?

[Norton]

In the first and mid part of the walkthrough (30 ~ 40), it does work as intended.
But now at level 53, it consumes ammo.
Is there anyone who knows how to fix this?
(I've tried sharpshot, hunter bow)

[Sédrio]

Valor skills have three levels you can use. For powershot, it's level 1 (3 shots, 150% dmg), level 2 (4 shots, 170% dmg), and finally level 3 (5 shots, 200% dmg AND does not use ammo). So you need your valor bar to be full and then activate it to have a Level 3 Powershot which does not use ammo. Anything less than a full bar will activate the lower levels instead.