Hunter-theorycraft:
Volley, 6 seconds channeled no haste.
A shot every 2 seconds.
I do about 600 damage with one hit with Volley, around 1-1.2k with a crit, I have 15% crit chance (BM spec)
5 Volleys without crits to kill.
Volley is 17% of base mana.
5 Volleys is 85% of base mana.
You'd need to spec 33 to MM for Volley to not be pushed back by the damage you will take and even then, you would need to take all the damage from the mobs attacking you.
Doable? Mayby.
Usable? No.