The Chapman Gun Kit screwdriver set. This was recommended to me back in the 1970's and has come in handy so many times. The bits for this are hollow ground, and resist camming out of a screw slot. Sometimes you find very slender slots in screws; some of the Chapman bits are ground thing to accommodate these. I don't know if they still make the 9600 kit that I first bought. Later, I added supplementary sets for hex (Allen) fasteners, and in the recent past, Torx. I've also bought single bits of the numbers that I've broken, and spares of those most likely to break. It came with a couple of cross tip (Phillips) bits, but those are not all that common on firearms. Butt plates, mostly. So I never bought a set of cross tips -- but I ought to, as this kit does see some use outside firearms. The Allen and Torx aren't often seen on firearms (mostly scope mounts). There aren't all that many Phillips tip sizes so I guess I just figured on regular screwdrivers for those when needed.