I use a piece of 1/2 inch steel tubing that I epoxied a drill bit into so it would chuck up into my drill without any trouble. I think the bit I used was a bit driver of some sort, maybe even a hexhead driver. However, I have never tried to tun my bodies down either, I just use them round and the bass seem to like them. If i want a different shape/sound I make them square cutouts and taper the back edge for a popper, taper the front for a slider. the square face poppers make a heck of a ruckus, and are my current favorite. I'll try to post a pic later.
Wet wadin' hillbilly extraordinaire
Man is most nearly himself when he achieves the seriousness of a child at play.
Heraclitus