If you have a barrel vise and a Luger receiver wrench, it can be a quick & easy job. The barrel vise insert can even be used in the lathe chuck. The pic below shows a member doing something with a barrel that has been removed from the receiver. The aluminum insert is a two-piece part, and the chuck is a 3-jaw. I assume the member centered the bore before machining.
G.T. has considerable experience in Luger barrel work of this kind.
