Anyone out there ever cut bamboo flooring into squares and turn into shafts?  If so, how'd they turn out, spine, etc.?

Never tried it.

i would imagine they would be to heavy in weight, and too low in spine. never know if you don't try though.

Like I said on the other board, flooring is no good for arrows.

I read in a past issue of Primitive Archer about a guy that laminated bamboo for arrows. I do not recall what all he did but as I remember it he ended up with a hard wood lam in the mix to ad spine. You may want to do a search for it.