I think your right on a diamind bit they can be had a harbor freight in a set for around $30.00. I paid that for a set of diamond burrs a bunch of different sizes and shapes. I wonder if the rod is case hardened? A gun smith can tell you how to annel a small area to drill it if its hardeded at least I heard that from someone. I'm not up on it. I think you have to heat it up to a red color and stick it in lime dust or something you might look it up on the web or ask your friendly gun smith.

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norms-iron-works.tripod.com
motor assisted bicycle engine headlights that work off of your white power wire. check it out