I bought from Brownells their master set of bits and a few extra handles of different lengths. Prior to that I had a couple sets of "Chapman" bits and handle and always kept one set in my shooting kit. I lietrally cring when I see someone at the range whip out any old screwdriver and commence to winding in or out action screws or scope ring screws. Nowadays good allen wrenches and tourx bits are on scope ring screws and action screws. Bondhux and Brownells sells both. Frank