Heavy tips, heavy outer limbs, uneven tiller, too much bend in the handle, stretchy strings, and very light arrows (like CF arrows) will all contribute to handshock. Anything which causes excess vibration. I made a hickory backed osage Holmegaard bow a few years back, and the handshock was so bad, it would loosen your fillings. Brutal. Very unpleasant to shoot. Heavier arrows helped, but not much.
