Gear Rifles - design assistance requested

[Anthony]

Originally Posted by Varyon

What I like about the "chaingun" idea is that it's relatively simple - just gears in the stock spinning to spin a linked chain.

The problem with the chain idea is that you have to move the entire chain to move the projectile, which means you have a large efficiency loss unless either the chain is very light, or you can keep the chain spinning between projectiles.