Must be a sign of the Alzheimer's setting in ? 14 TPI ,
The important thing is a Taper turning attachment, one of these and your in business, but to be honest, most barrel blank suppliers will contour any blank for little cost and I know Lothar Walther charge approx $65, 41 pounds (pound sign not working on laptop) for the ammount of time setting everthing up, and your own time on the machine etc, more cost effective to let them do the contour including the Tenion, the finish is excellent, so you will have a blank with correct contour and a machined tenion ready for the thread and chamber.
Most expensive part is the Chamber, If you buy your own reamer easy enough to do, Think in the USAyou can rent them? that leaves the thread, no need to worry about the thread start, just machine thread and add knox form on completion of the final CHS.
One cheaper way of doing it, is to look out for any old target rifles based on the No4 action, plenty still about with hammer forged barrels, still may need to make a spacer etc for correct CHS and still need a reamer.