Dave Lay -- the nail sounded like a great idea, so I tried it. It is and it isn't. I used an 8d finish nail (no head to cut off) and an 11/32 cedar. Drilled the hole freehand with a hand drill, glued in the nail, tapered for target head, and she shoots just like before, no problems, with a 27-grain weight gain right up front where it belongs.
Ah, but then I tried it again today with another arrow and my hand wasn't so steady and the drill bit ran out the side and I now have another 2-short stump arrow I didn't need.
So, what we need to make this a consistently workable trick is some sort of gig for drilling straight into a shaft ... which is as difficult to arrange with a drill press as with a hand drill. Aside from having to drill 2+ inches into the shaft without going astray, if the head of the nail isn't precisely centered, you're in trouble when you taper for the point.
In sum, this is a great idea, but we need a simply drilling gig to make it work. Any ideas? Thanks, Dave