James is right about running in a steady rest to crown or thread, but if you don't want to mark the barrel where the steadyrest runs, you have to make a rider ring, and if you are recrowning a barrel that has a front sight that is sweated on it, you can't get a rider ring on. One big advantage of a rider ring is that after it is in place, you can turn its O.D. concentric with the bore before setting up the steadyrest and removing the tailstock center. All this is very time consuming for a simple crown or muzzle thread.
If you can set up in the chuck, the sight will sometimes go between the jaws of a 3 jaw, or if you are careful, you can chuck up behind the sight and take very light cuts. You can use brass shims or card stock to protect the barrel finish and to push the bore axis true whether the barrel has sights or not.
One thing about the big hollow spindle lathe, if you fixture up, you can shove a short barrel into it receiver and all. JECustom told me years ago that a big lathe can do anything a small lathe can, plus a lot that a small lathe can never do.
Random question, would it be harder to find spindle nose accessories, like a collet set, for the hollow spindle?
Nice problem to have. Good luck, Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time