The only thing I would add to the existing posts is this:
When you center punch, you make a little volcano, not just a hole.
It is helpful to file off the "hump" so the drill bit doesn't catch on
it and begin its wanderings before you even get to the bottom of the
punch mark.

Pete Stanaitis
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John Emmons wrote:

Why do holes made by normal twist bits almost always end up being out of
round? Even with my drill press.

A reamer cleans them up but what causes the problem in the first place? And
is there anything I can do to minimise it?

Thanks.


John E.

"when hatred calls with his package, refuse delivery..."