It seems that a lot of the compound shafts had a lighter material for the main shaft and heavier material for the foreshaft. I have some syringa arrows i drilled out very carfully with an electric drill, i recomend trying it by hand. I plan on making forshafts out of heavier material since syringa is a bit light. Ishi drilled hazel shafts and inserted forshafts, cant remeber what kind. I also am going to try red osier compound shafts. Ocean spray is a great heavy shaft material. good luck.
I would hold the arrow in one hand and the drill in the other and slowy drill out th hole with pulses. I recomend doing it by hand, i did crack a few arrows that way. I would bind the shaft before you drilled it.