Well, I had hoped I would be able to ignore this problem, but I've got a player at my table who has a fairly firearms focussed character. (As strongly as one can get right now at least, three aim, and deadeye)
So I return to one of those plaguing issues, what is really stopping this player from going full blackbeard and bringing along 4 or more pistols to completely incapacitate a villain in only a few rounds?
It feels arbitrary to limit the number of pistols they can carry (obviously not to a ridiculous degree, any attempt to carry a dozen muskets would be shot out of the water)
But otherwise I'm grasping at straws to avoid the issue. The closest I've come is allowing villains to spend raises in order to try and avoid the shot, one success still guarantees a dramatic wound, but anyone truly dedicated to dodging an innacurate flintlock pistol is probably going to be able to do it (except against a more amazing shot)