[iraiam]

I use ground pins that fit the bore to dial indicate to, my dial indicator is a Mitutoyo 2109S-11, accurate to .004 mm (.00015"), although I think actually indicating to within .00015" is probably beyond the tolerance of my machinery.

I either use a 4 jaw chuck, or I made a barrel jig that goes on in place of the chuck and has 2 sets of 4-way brass tipped bolts as adjustments. I was thinking of re-making the barrel jig with fine thread bolts, to hopefully make it easier to dial in closer.