I have just done a bit of an experiment in the hole industry!! I have tried using a round ended router cutter on some box held in my 4 jaw chuck. The cutter worked great at 2000 rpm and as the hole was far too small I just loosened the tail stock clamp pulled the tail stock slightly towards me and enlarged the hole bit by bit to the required size. All you need to do is take small shavings and not go quite as deep each pass. Sanded with 80 grit to start and I now have a nice slightly tapered hole. I have to go out now, but if I get chance on return I will post a couple of photos..