Almost all gun work requires screwdrivers, and it is important to use those that are properly designed for such work and that precisely fit the screws on which they are to be used. Never use a standard, “hardware store” screwdriver on a gun screw.
   Most screwdrivers sold in hardware, home or auto-supply stores have flat, tapered sides. This allows them to fit a wide variety of screw slot sizes, and it also adds strength. But they are a horrible choice for working on guns because a tapered blade will cam against the screw slot’s upper edges as you apply pressure and cause the screwdriver to ride up out of the slot and go skidding off and gouging anything in its path. It may be your hand, which will likely heal. Or it may be the gun, which could leave some ugly, new engraving on it forever. Either way, it is guaranteed to ruin the screw, and will likely make removing it difficult without drilling.
   The pressure exerted by a screwdriver is terrific when it’s applied to a very small area. That’s why a screwdriver must fit exactly into the slot of the screw on which it is used, both in thickness and in width. I cannot stress the importance of this enough. The blade’s profile should be of the hollow-ground design. Viewed from the side, a hollow-ground screwdriver blade or bit has a radiused profile that allows its sides to be completely parallel at the bottom. Such a profile allows hollow-ground bits to apply pressure at the bottom of the screw slot, rather than at the top as a tapered screwdriver does. This actually helps to “lock” the screwdriver into the screw as opposed to tying to cam it out.
   A hollow-ground bit applies torque along the entire length of the screw slot, distributing the force over a much larger surface area than a tapered screwdriver could. The proper bit or blade applies more leverage by directing torque out at the very edges of the screw head. This is a simple principal of leverage. With all else equal, it’s much easier to turn a large wheel than it is a small wheel. There is little point in having a large wheel to allow more leverage and then only turning it from the halfway point, which is closer to the axis and allows less leverage. It turns easier when the force is applied to the leading edge of the slot, which is the farthest point from the axis.

To avoid galled or stripped gun screws [1] use only hollow- ground rather than flat-ground blades on firearms. [2] Many of the 89 bits in the Wheeler Engineering screwdriver set [3] are built for specific firearm applications. They include an S&W rebound spring compressor tool, a Mauser stock bolt bit, an M1/M14 rear sight bit and an M1911 stock screw bushing driver. [4]

   In days past, gunsmiths spent hours filing the blades on screwdrivers until they fit perfectly into the slot of the screw they wanted to turn. Today, we have better options. Simply choose one or more of the many different screwdriver sets available that are designed for gun work. Some are fixed blade, but the most economical are the sets that use detachable bits with a single handle. This also allows you to have bits for Torx head, Phillips head and Allen head screws.
   There are several excellent kits on the market. The Wheeler Engineering Deluxe Screwdriver Set sold by MidwayUSA is one of the most complete. Wheeler’s engineers measured the screws on more than 100 modern and antique firearms to make sure that it offered bits for every situation. There are 54 hollow-ground flat bits that range in size from 0.120"x0.020" to 0.360"x0.070." That includes doubles in the thinnest sizes, because even the best bits will break now and then when they are this small.
   The set also includes a complete selection of Phillips, Allen and Torx bits. Some of the “professional” set’s best features are the 17 specialty bits. The set comes with a regular size handle that’s suited for most jobs, and a slimmer, shorter “Close Quarters” handle good for finesse work with smaller bits. Everything fits in one plastic case.
   You will also need a set of small “jeweler’s” screwdrivers for some of the more delicate work you will encounter. MidwayUSA sells the Wheeler Engineering Mini Screwdriver set with six screwdrivers. A long, thin-shank No. 2 Phillips head screwdriver is handy for removing recoil pads. Pick one that has a round shank and is polished and chrome-plated. You want it to be as smooth as possible to reduce the possibility of tearing the rubber in the pad. Also, you will need a long (about 12") and fairly large flat blade screwdriver to reach into the butt of shotguns and some rifles to remove the screw that retains the buttstock. There are specialty screwdrivers on the market for this, but a high-quality hardware store type will work fine for most guns.
   Another screwdriver that I have found useful has a big, wide tip that I filed a notch in for removing over-tightened nuts on Weaver tip-off scope mount rings. The screw often extends out past the bottom of the slot and prevents the screwdriver from seating fully. The notch allows the screwdriver to reach past the screw so it can seat properly in the slot. The big handle provides plenty of power to remove the nut.
So, remember, the next time you approach a gunsmithing task that involves removing or installing screws, select the right bit and you won’t screw-up.