I have a part coming up that has a .900 deep .154 diameter hole. It has a .0005 concentricity callout between 2 outside diameters. One of the dia is only .004 smaller than stock size. I always have problems with material swelling and putting conc. to .002-.006. I am using G821 to keep material as close to guide bushing as possible. Drilling is done first so that it is supported by guide bushing. Any tips for a good drill or method to help this? Cycle time is exrtremely critical. Thanks