Zakharra wrote:[snippage fore and aft]It's still too soon for them to have even a primitive Gatling.
Do recall that the original Gatling design used black powder and percussion caps loaded on to iron cases. (I hesitate to describe them as cartridges.) This is something Charis could certainly do.
The great thing about gatlings is that they're not self-loading; like other externally powered automatic weapons, they're tolerant of cartridges that don't fire. Self-loading weapons like the Maxim aren't. When you're still figuring out the whole mass production of ammunition thing with new chemistry and new technique all over the place, that's likely to be valuable. (So is not having to figure out disintegrating-link belt feeds. Those are fussy.)
The tricky thing is designing a gatling-style rotary cannon; it's not obvious. Gatling was a very clever guy with mechanical devices. There may not be someone from the Inner Circle handy to get quite that inspired in such a specific greasy mechanical way.
You can spin a gatling with compressed air or steam; the USN had them in calibres up to 1" until the first decade of the 20th century for fending-off-boarders sort of roles. (Another decade of institutional inertia and they might have been adopted as anti-aircraft technology in the 1920s.)
It's not hard to imagine the Charisian Navy deciding that the smallest size that will get them a bursting charge is just the ticket for anything other than anti-shipping on the inshore ironclads. You don't need the high a rate of fire of modern aircraft gatlings, and you've already got the compressed air and the heavy pintle mount for a 4" quick-firer. You could probably do a "1.5lbr" -- 37mm -- as a five barrelled gatling at a couple hundred rounds per minute with a gravity feed from a hopper -- the original gatling design -- and some busy loaders. Doesn't need an especially high muzzle velocity, either; the point is to have HE shells that explode, so you can chew up anything made of wood and troops.