https://www.youtube.com/watch?v=f1r56_Rb8TU

Semper Fi,

I think this guy is missing the point of why this type of set-up is used in the first place. The chamber and shank should be cut perfectly concentric to the "bore" of the barrel NOT the OD. I seriously question the accuracy of a dial indicator that is set up 15-20 degrees from perpendicular to the work. It's an honest effort but attention to the details is what makes or brakes a project.