I would like the idea if they are something in between crossbows and throwing weapons in balance. We have the one hit throwing lances (3 ammo per stack) and the sniper crossbow, with a lot of time reloading but 15 bolts.
The main problem here and the reason because ranged spam is annoying is that you can't do anything against it. If a melee soldier kills you, you know it's your fault, you blocked badly, there were too many of them... if someone one-hits you instantly with a very fast projectile you cant do anything (you can't even try to dodge it).
Even if the weapon is "balanced" it would be because it kills more people slower, but not less efficiently. The people who got killed would be still annoyed.
Anyway, I would be ok with it if it needed 3 slots like someone said (bullets, a horn, and the firearm). Something between 5-7 bullets, more acuraccy than a throwing weapon and less than a crossbow (more or less in between), 2 times the reloading of the sniper crossbow, no need to adjust height, more projectile speed (a lot), and the damage of the sniper crossbow or slightly more. However if heirloomed it shouldnt be more than the masterwork sniper crossbow (so it doesn't one hit armored people). And be veeeery expensive, the worst one should be like the sniper crossbow.
In this scenario, only badly skilled people and people who likes firearms would use it, with no more unbalancing than a sniper crossbow or throwing lances (which should be nerfed in my opinion).
An interesting idea would be that they are very heavy and requiring WPF in order to be wielded BUT not to become better at its use (if this can't be done, then... engineering skill?). This along with the 3 slots ,weight, and money needed, would mean you cannot become a master firearm character or a very good hybrid.
Poll