If you think the end mill is flexing then instead of running a single pass run it a second time. If it is bore is bigger after the second pass then you have flex.
Dan Mauch
Since I use a CNC to cut holes for my bearings, I can make them any size so I decided to investiga te press fits. I found that with a bearing OD of 0.875", a press fit in plywood was -0.005" and in Oak -0.009". Kind of surprisin g but I figured it had something to do with cutter flex using a 0.125 end mill. I'm sure that machine calibrati on is critical when dealing with these small differenc es. I would be intereste d in hearing what others have found if they did any experimen tation.