If you want a truly round, exact size hole, don't use a drill bit. I drill those kinds of holes a few thousandths undersize, and finish up with a chucking reamer. Having a bunch of flutes in a complete circle instead of two cutting edges keeps the hole round and the right size, especially if you're using a drill press or the tailstock on a lathe to hold the bit.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!