So the route Pathfinder went to show the power and penetration of firearms was to allow them to resolve as touch attacks, rather than regular AC attacks. In addition to giving them a x4 critical hit damage multiplier. Never in a million years would I have thought of this as a good way to represent the strength of firearms. When we used 4th Edition to play in Hekinoe the way I did it was that each firearm had a bonus to attack rolls when attacking an armored foe. Which when you think about it for ten seconds, makes absofuckinglutely no sense, as it makes it easier to hit a person in like leather armor than someone wearing no armor, as the bonus to the roll not only neutralizes the armor's bonus to AC, but still has attack bonus left over to help hit the target on top of it all. It was a wonky inelegant system. But most of what I did with Hekinoe with the 4th Edition ruleset was wonky and inelegant because 4th Edition just fucking implodes if you try to add any non-high fantasy elements to it.
So one of the features that differentiates firearms from bows is their penetrating power. Don't get me wrong, bows are nasty. Arrows are long and have sharp metal bits that hurt. They can do a lot of damage to a body and are a fairly precise and deadly weapon when used by a skilled archer. However, there's a reason modern military forces uses rifles and handguns instead of ye olde compound longbow, or a modernized equivalent.
Based on the way firearms resolve their attacks against touch AC, I am considering the possibility of crossbows and bodkin arrowheads resolving in a similar way.
Crossbows have the potential to put much more tension on the bow than a human's arms can, and thus can impart a bit more energy to the projectile. I'll be honest, I am not any sort of authority on archaic weaponry or its modern variants. I just bum around Wikipedia a lot and read a lot of fantasy novels and game manuals. So my understanding is that the mechanisms of the crossbow give it more impact force than a longbow pulled back by human limbs. My understanding is that this gives the bolt more penetrating power than an arrow, in addition to other pros and cons that are irrelevant to this discussion.
My understanding is that there are also these things called bodkin points for arrows. Now we've all seen little target arrowheads and the big fat blade-like broadhead arrowheads. Bodkins are these narrow little kind of square shaped arrowheads. Supposedly this shape leads to greater penetration from such arrowheads. Theoretically, it makes sense, as it concentrates all the force of the impact into a very small area rather than the larger surface area of a broadhead. I kind of think of it as the difference between getting your hand stepped on by the heel of a boot and a stiletto heel. All arrows and bolts are more or less designed with a point because it concentrates the force of impact into a smaller point, but bodkins are still slimmer and more pointed than most other arrowheads I've seen.
So with these thoughts regarding firearms, crossbows, and bodkin points in my head, I am considering creating bodkin arrowheads for the game and allowing bodkin arrows and crossbows to resolve against touch AC like firearms. I think I'd restrict it to the first range increment though, like early firearms. We use advanced firearms in Hekinoe, so they get to resolve against touch AC within the first ten range increments, and I want firearms to still be unique. I'd obviously make bodkin arrows more expensive than normal bow ammunition, and maybe tweak the costs of crossbows as well, or restrict this ability to the bigger crossbows. Not sure. This was just a kind of interesting thought that occurred to me.