Gear Rifles - design assistance requested

[Varyon]

Originally Posted by Anaraxes

One option I forgot to list in the gauss rifle thread that seems steampunky would be the method famously used in the Whitworth rifles (both small arms and cannon) in the late 19th century (American Civil War era, though Whitworth was English). Hexagonal barrel with a hexagonal projectile to match. (The small arms had hexagonal cross sections; the cannons had projectiles that were also twisted, so they look spiral-shaped.) The orientation of the hexagon rotates down the barrel. So, no grooved rifling that bites into the bullet; instead, the has flat surfaces that match the barrel all the way around, rotating as it moves down the barrel because the barrel itself twists. Your plan started with an elongated bore to have room for the chains; rotate that all the way down the barrel.

The Whitworth small rifles would also fire cylindrical bullets if they were made of soft lead. Polygonal rifling without the fancy ammo has been used in a lot of weapons, including fairly modern ones.

Anecdotes say that the Whitworth cannon projectiles made a distinctive and peculiar screech as they flew through the air, which also might be an appealing detail just for color.

ACW-era is a bit late for what I have in mind, but those do sound pretty awesome. I was considering smoothbore longarms (powder or piston driven) to have Acc 2 (pistols would have Acc 1), while rifled ones would have Acc 3 (pistols would have Acc 2), with double barrel cost (I separate the cost of the barrel, the breach, and the stock for firearms; for gear rifles, the piston mechanism and battery would also have separate costs). The Wikipedia entry on the Whitworth notes it had increased accuracy but was around 4x the cost of a Lee-Enfield. I'm thinking such hexagonal barrels may well be available; they'd increase Acc by a further +2 for longarms, or +1 for pistols, with the option in either case to get another +1 by using special expanding ammunition (like the soft lead bullets of the Whitworth, which had a Minie-style expansion when fired); barrel cost would be x10 compared to smoothbore (x5 compared to rifled), and the special ammunition would be +2 CF. This is in addition to the options to make the weapon Fine (Accurate) for +0.75 CF and +1 Acc, or make the ammunition Balanced for +4 CF and +1 Acc (a dedicated marksman's rifle would have a hexagonal barrel, be Fine (Accurate), and use Minie-style, Balanced bullets, for a grand total of Acc 8 - on par with a modern sniper rifle firing match-grade ammo, which is pretty ridiculous but... whatever, it works).