"but for the zone you can find it it's just the best thing far and away."
I can see that.
I don't know, i haven't used it that much, but i found it generally inconvienent to use. Probably not easy to use in really frantic situations.
Making cost 2 is overkill. I would honestly find it really bad then. Maybe 2 ammo and a buff to the bolts could work.
I'll totally decrease the damage of the explosion, and probably reduce the fire rate.