Madsenshooter, I know at least some of the European Krags have left hand threads. Is there a list published some where that tells which have which?

Kooler, Anyway you can mount it in the lathe with the action attached? If your lathe has a reasonably short spindle it might allow you leave it together and just spin it a little slower to deal with the weight imbalance. Most doing this work will use a 4 jaw chuck on the small end of the barrel with a copper wire wrapped around the barrel to prevent marring. Ones that do the work all the time will have a "cat's head" on both ends of the spindle. They use soft brass screws in the cat's heads to prevent marring the barrel. If you do not have a cat's head for the outside end of you spindle they are not hard to make, I made one for each of my manual lathes. If you do not want to do that you could use tapered wood wedges to more or less center the receiver end of the barrel. On the end you are going to face and crown indicating to .001 TIR will be good enough, if I was threading it for a muzzle break or something critical I might try for closer.

If the concept of a cat's head is new to you might do a google search. I bet there are lots of examples on youtube. Many have been shown in Practical Machinist in the gunsmithing section, but I think you have to be a member to view the pictures. I can take some pictures but it will be later as the cattle need working real bad to day.