Have you ever had trouble with an ordinary slotted screwdriver, and the screws it purports to drive? Did it slip, and mar the object you were working on? Perhaps it left the slot scarred up, promising an even more difficult job the next time you have to take out that screw. I have had those troubles too. And the reason is simple: ordinary screwdrivers aren’t made to fit screws! That’s where gunsmith screwdrivers come in.

This picture tells the tale.

Image showing how gunsmith screwdrivers make more contact with the screw slot than regular screwdrivers.
Source: http://armsinfo.com/screwdrivers.htm

The ordinary screwdriver is on the right, and the gunsmith screwdriver is on the left. The ordinary screwdriver is sort of wedge-shaped, while the sides of the gunsmith screwdrivers are parallel, at least where they actually touch the screw slot. As you can see, the ordinary screwdriver only transmits power to the screw via the edges of the slot. But the gunsmith’s screwdriver transmits power along the entire depth of the slot. If you apply the same force on the screwdriver handle, the force on the screw will be spread across a very small area with an ordinary screwdriver, and a much larger area with a gunsmith’s screwdriver.

Why does it matter?

Time to let another picture tell a story.

Image of raised burrs on screws caused by not using gunsmith screwdrivers.
Note the raised burrs on the edges of the screw slots. That’s the calling card of an ordinary screwdriver.

An ordinary screwdriver caused the damage you see to the screw heads. Since the screwdriver put all of its force against the tiny area of the edge of the screw slots, it created enough pressure to push the metal away. That created the raised burrs.

Sometimes that burr doesn’t really matter. The screw still works, and you’ll be able to operate it many more times. If you won’t see the screw normally you probably won’t care if it isn’t perfect. But if the screw is visible, and attached to something expensive, you just might find that burr annoying. And if you have to handle the part with the screw, you’re sure to feel the burr, which also isn’t great.

Naturally, the tighter you make the screw, the more the head will distort, so if you have to tighten a screw down really hard, it’s possible to damage the screw so badly you won’t be able to undo it, or use it again. For most screws, you can find a replacement at the hardware store. But if the screw isn’t standard you’re out of luck, so you’d better not damage it.

As you might imagine, the owners of rare antique firearms aren’t too keen on scarring up the screw heads, so using the right screwdriver becomes really important.

Why aren’t all screwdrivers gunsmith screwdrivers?

At this point you might be asking yourself, “since gunsmith screwdrivers are so great, why aren’t all screwdrivers made that way?” It’s a good question, so I will answer it with another question. Is driving screws the only thing people do with slotted screwdrivers?

Of course, the answer is definitely “no”. Every self-respecting shop textbook piously proclaims that screwdrivers should never be used to pry anything. But everyone does it. Ordinary screwdrivers hold up to a little prying pretty well. But the ground tip of a gunsmith screwdriver has a sharp shoulder where the ground part stops. And that sharp shoulder is a stress point that is prone to breaking. That isn’t a problem for twisting a screw, but that makes a gunsmith screwdriver a poor tool for opening paint cans.

Then too, for most jobs, a little burr on the screw head just doesn’t matter. Lots of screws are hidden inside of mechanisms, or in spots that you just won’t see them, like the underside of a desk, or inside an electrical box in the walls of your house.

Of course the biggest reason is simply cost. You can make screwdrivers a lot cheaper if you don’t grind the tips. If you make them cheaper, you can sell more of them, or make a bigger profit on each one, or even both. As long as nobody complains, companies won’t bother to grind the tips.

Where do you get gunsmith screwdrivers?

You can find gunsmith screwdrivers in a lot of large sporting goods stores that cater to hunters (Cabelas, for example), as well as places like Brownell’s that sell gunsmith tools and supplies. I bought a set made by the Grace Company, but there are several good brands.

If you want to do really high-quality work, I really encourage you to get a set. But keep them in a secret spot, so nobody employs them as a pry tool!