The accuracy isn't an issue, you can see in one of the photos that I put up where we are probing the part. I have a calculation that automatically compensates for the o.d. runout as the part runs. The dilemma I have is we already purchased the holders(about 300 pcs in all) so I doubt we would be able to trade them in. Also, where could I find an arbor type hydraulic holder? I have yet to see one of these.