With a fast projectile speed it’d be a straight upgrade on bows, having the same performance against SV without the projectile drop and ammo issues, while annihilating any unarmored enemies and hordes and being the best ranged weapon vs chaos warriors.
I’d have said bolt is the most versatile, strong vs hordes, strong vs all elites and specials, only somewhat mediocre on bosses. Fireball sacrifices elite killing, special killing and range for extreme horde clear.
Because having a weapon completely better than another in every regard, all the while having more ammo, is not good balance.
They both do the same damage on a headhit, the handgun does more on body, but sacrifices rate of fire and a lot of ammo to do that.
While bolt is stronger vs elites and specials than fireball i’d say fireball is more useful in that it’s lmb has crazy stagger and you’ve got a much bigger ammunition pool for lmb spam vs bolt charged. Imo of course, havent used bolt enough since i find it lackluster.