Quote Originally Posted by Indon View Post
Never used a crossbow here, but it seems to me it'll have less of a kick than most firearms simply because it employs less force in its' firing. Combine that with a large enough weapon to absorb some of the force, and you get a recoil that seems negligable, particularly to someone accustomed to firearms with signifciant recoil.
The thing is, a good portion of the bow itself moves forward upon firing, and the bolt's mass relative to that of the bow is higher than a bullet's mass relative to that of a gun. So when a crossbow is fired a lot of the total mass moves forward, causing more recoil than you'd expect. And if by "siege crossbow" you mean "ballista", those can have a lot of jump when they're fired.