Acoustic Guitar Construction

I'm tagging along on this thread, as I have some of the same general concerns as this thread addresses - - - nearly:

My kit guitar neck's tuner holes in the headstock were pre-drilled to 7.5mm for the nut that threads into the inside diameter of the shank on the tuner body, so a 7.5 mm diameter nut threads into a 10mm diameter tuner housing. Is my inference correct that I can drill out the headstock's 7.5 mm holes to 10 mm and pay no attention to the bit of the hole in the headstock that winds up oversize for the nut? Sure sounds easier than trying to counterbore the relief for the tuner body out to 10mm and leave a bit of the hole at its original 7.5 mm diameter.

Thanks, folks.

If I'm following you correctly - Yes. The entire hole can be 10mm. You have something like a Grover Rotomatic or Gotoh tuner with a bushing and nut on the top side and one screw hole on the back side?

What I do is chuck a 7.5mm bit into the drill, insert it into the headstock, secure the headstock in place, then change the 7.5mm bit out to the 10mm bit and the bit will now be centered with the existing hole.

10 mm holes --- the step drill idea is a solution looking for a problem, the illustration in the supplier's ad makes me chuckle. Tim's centering procedure is spot on.

Well of course. I knew that (!). But I didn't manage to make the association that knowing how to center an enlarged hole in general was also the sensible technique for my particular tuner-hole problem. Tim, thanks for the heads-up, and Ken, thanks for the affirming comments. Time to visit the drill press.