I was watching some videos on one of my shotguns. The gunsmith started out by making his own set of screw drivers for dis-assembly of the shotgun. So the first 10 minutes or so is showing how he makes his screw drivers
It's not on youtube, so either go the the videos page, and then click on the "Browning A5 Disassembly"
or can hit the video file directly below.
We used to make screw drivers as a shop project in HS, haven't really done them since, usually just regrind an old one I have laying around, but he covered how to do hardening in the video, which I thought was worth watching.