Bill Schwab wrote:

I am getting closer to doing the job that involves clamping open boxes,
DB 9 holes, etc. There will be some round holes, and my first thought
was a boring head. That would be overkill in precision capability, but
I'd like to learn how to use one, so it seemed reasonable.
[...]

Non-standard sized large round holes?
Thin metal (steel or aluminum?) boxes?
Using a drillpress or a mill or something else?