Same as above.
I use two 001" indicators to get it as close to zero as possible. Then swap them for two 0001" indicators. As I am not doing this as a business but for my own use. I take the time to get the 0001" indicators showing zero movement when the 4 jaw is spun. Can take long time to get there when you first start. It took me an hour and a half for the first barrel that I ever set up in the four jaw. Now I can do it within 20 minutes to half an hour. Some professional gunsmiths will laugh at this but they do not know how long it takes to get to zero runout. 0002" is acceptable. Time means money. Most uses bushes to centre the rifle I watched a youtube video where a gunsmith, (Riflesmith, whatever title you wish to give) Did not use a dial indicator for any part of the set up procedure.
I believe you get out of anything what you put into it. When $$$$$ become involved the need to speed up the process to make it quicker becomes the norm.
You will probably find that most well known target shooters do their own barrel work.
The Professional out there probably aint going to like this but it is fact.
Cheers