Gear Rifles - design assistance requested

[Varyon]

Originally Posted by Donny Brook

I wonder if a grosser movement than cranking could be a faster way to charge the weapon, like a long lever or a pull-cord.

I suspect not. A goat's foot takes 20 seconds to use and increases effective ST by 30-40%. A windlass takes 9 seconds to wind up the crossbow, and increases effective ST by 50%. Overall, I think using the two ends up taking a comparable amount of time, but that's because a windlass takes longer to attach and detach than a goat's foot. So I think winding is probably the most efficient. Note also that most devices that use muscle power to charge a battery also use cranks (some instead have you shake them, but personally I feel the winding ones work better).

Originally Posted by thrash

Not meaning to quibble, but the point of the "Red Ryder" piston mechanism (vs. historical air guns, which did use a reservoir) is that the energy is stored in the spring, not in compressed air. You increase the pressure delivered by making the piston much larger than the bore. Another benefit is that the pressure is consistent, rather than diminishing as the reservoir empties.

Again, a spring (particularly a coiled spring) this strong isn't historically accurate, but it is probably minimally invasive as unobtainium goes. Maybe they have to be harvested from Hell Gnome traps...

Ah, I misunderstood you. Looking it up, it looks like you could base it on a fire piston, but with a narrow tube at the end the air can escape through... once it's accelerated the bullet wedged in there. It would still need to be something that you can charge over the course of several seconds (to generate enough force to propel the projectile at a higher effective ST), but seems workable, still with something soft to cushion the impact of the piston striking. It doesn't have all the clockpunk accoutrements, but has a certain simplicity that is enticing. And it makes rifling as simple as, well, just rifling the barrel. You do need the bullet to be largely flush with the walls of the barrel (to prevent air from escaping around it), but soft lead (or a softer wax jacket) should help with that. I'm not sure a flechette would be possible, although perhaps if it's contained within a sphere of wax? It seems like that would let it fit snugly in the barrel, then when it impacted its target the wax layer would be left behind, with the flechette simply cutting its way out and into the target. It also seems like a longer barrel wouldn't be as useful - for firearms a longer barrel means more of the powder burns before the bullet leaves, but this has all the pressure generated in an instant, going down as the bullet travels down the barrel. Perhaps this mechanism is (somehow) less efficient, but is used for pistols and short rifles, where its inability to benefit much from a longer barrel isn't an issue? I'll have to think on it.