OK. Progress. Only have one bit that will fit the #3 Morse taper of the tail stock. That determined the caliber. The hole it cut is about 0.82" in diameter, which says if I bore it I can open to about 0.88 which will fit (with a little windage) the 0.875" diameter OD of 3/4" copper tubing.
Two pictures:
First chips:
Depth of bore:
I'll probalby leave it at 6" length of bore and cut the overall length to 10" (turned portion in previous post).
That will leave 2" inbetween and 2" hole depth for the staff.
One fun thing that happened in the process of drilling the bore: the tailstock will extend a little over 4". With no warning, it locked extened at just over 4". A quick switch to the other tail stock and continued work.
Ok, the tail stock now only cranks out 4". So to drill 6" deep I had to shorten it, slide the tailstock forward and drill inside the existing hole, lock it in place, drill a little. Unlock it, slide it back to clear chips, repeat.
Hmmmm. New tools are made on old tools. I guess that's life.