Just came up with a new weapon. 

Take an aluminum tube, 3' long, inside  diameter 1".  Get a tungsten-carbide bearing, 1", or slightly less, in diameter. Add a handle to one end of tube.  Place bearing in tube.  Place a loose fitting rubber foot on the other end of tube.  Use as cane, concealing weapon aspects.

To use as weapon: Raise the cane; remove rubber foot; swing at target such that the bearing inside flies at the target, hitting it with great force.  Range at least 100 yards.

Timpa did this at one point.

https://www.youtube.com/watch?v=zhdOKTSP584

Sure.  Bamboo is solid at the nodes.  So the 'barrel-length' would be limited to the stem between nodes.  But that should definitely work.