OK, here's what I have so far...Picked up a Yugo AK barrel awhile back that had some galling where it had been pressed out of the trunnion (common on these barrels). Seems the way to fix that is to weld up the galled area, rough grind it close to final dimension with a dremel, then place in the lathe to turn to finished dimension. Here's where where I'm running into trouble... I've got the barrel centered in the 4-jaw chuck on my Atlas 10100 lathe to within 0.0005, needle on DI barely moves when rotating the 4-jaw by hand. The barrel itself is 16.1" in. total length with about 2" in. of that in the 4-jaw. The problem is the remaining 14"in. of barrel hanging out in space. At the chamber end where the cutting needs to be done it's 0.019 runout according to the DI. The magnetic base of the DI was locked to the bed ways for both measurements (up at the chuck & 14"in. away at the barrel chamber journal). Question is how should I go about bringing the chamber journal end of the barrel into center so I can trim the high spots of the repaired (welded) section to match the OD of the chamber journal ?????..... Would using a live center do the trick or am I going to need to find a steady rest, or am I missing something entirely about dialing this in to get the barrel to run true so I can re-cut the repair back into spec. ?? The OD of the chamber journal is a press (interference) fit to the trunnion so it has to be held to 0.001 - 0.002 tolerance for the press fit. Thanks.