I have for years used Chapman's compact multiple bit set as a backup to grinding my own driver heads. Their heat treatment is such that the bit will break before the screw in situations where the screw is 'frozen" in. (You always have to remember to reheat-temper the bit when you grind your own - experience gives you the color required for correct hardness). They are great people to do business with and you can actually get a live human being on the phone when you call! (860-349-9228 or
www.chapmanmfg.com). They also have an excellent 1-page tutorial on tips for working with metal and wood screws so nothing gets buggered up.
I have found that a few common, high-production guns such as the early Belgian-made Browning Auto-5s require an extremely thin bit for external action screws, and of course any of the hand fit British and European guns require very thin bits indeed.
Threaded Mode