This was a quick job done with a piece of scrape. It was turned between centers. There's a 60 degree center in the 3jaw chuck. Each end is center-drilled and each end is turned 11/16" for use in a collet. Concentricity is under .001".
The threaded portion needs to be trimmed back just a bit but its function as it is. Action is a junk FN Venezuelan.
Can you see the cast bullet used in the set-up?
The arbor length was almost too short. It needs to be about 1/2" to 1" longer but as it is it works fine.