"Ed Huntress" wrote in message
...
On Mon, 21 May 2012 12:26:00 -0700, "Bob La Londe"
wrote:

Yes. I don't know how to drill gun barrels either. LOL.

Gun barrels are drilled with single-lip bits that self-center by
bearing against the work with the side that's opposite the cutting
lip. In volume gun drilling, both the work and the bit rotate.

I can't figure how you're going to get straight holes in your
application, but I don't see how gun drills would help. They're a
technique unto themselves, and kind of tricky.


Well, the idea was to make a guide for the drill busing to make the hole.
The protrusion is parallel and concentric on 180 degrees to the path of the
hole that needs to be drilled in it (already done by hand with just an
extension). The deep straight drilling was to make the guide. When push
came to shove my hand was accurate enough for this application, but I can
see future applications where it might be necessary to get more precise
angular alignment.