Disassembling Fine Old Guns: The Right Way, Part 1

As a working gunsmith neatness should always be your signature. You may not have ever given much thought to it, but the screws and pins on a firearm, as well as the areas surrounding them, and even the edges of the wood where it fits up to the metal, are the gunsmith’s trademark. Many people, especially knowledgeable collectors and shooters, will unconsciously look to those areas first when they pick up a firearm as an indicator of whether the gun has been apart before.

When a person sees perfect-looking screw slots and pin heads on a firearm that has been recently disassembled, it conveys the idea that a true master craftsman performed the work. Moreover, the overall impression is that the work you can’t see must be just as good as what you can see. The opposite is, of course, true.

When you come across a gun that has chewed-up screw slots, gouges or dents in the metal finish around screws or pin holes, scratches in the wood or slivers missing around tight-fitting areas, these are signs of poor craftsmanship, often indicating a lack of care by the person who worked on the gun last. The assumption is that the weapon was disassembled by someone who exhibited very little talent or knowledge of firearms.

In the same vein, we assume any work that may have been done to the inside of the weapon, which we cannot see, is just a poor as the external appearance. Some people might consider this all pretty superficial and that I am making much ado about nothing. That may be, but these superficial areas are the very ones that you will be presenting to the customer first when you hand him back his repaired gun. You might ask yourself: Which of these titles would you like to sign your work with?

The neat and trustworthy master craftsman, or the gun-butcher, who, after being entrusted with the customer’s prized weapon, ruined its appearance? As anyone who has worked on old firearms already knows, getting a screw or pin out of an old gun after it has been there for a century without damaging it or—even more important, without damaging the gun itself—is one of the more serious challenges we’re faced with. Usually, the disassembly process itself is only a means to an end, albeit a very necessary one.

There are various reasons for removing these fasteners: We may have to repair some internal damage, or it may only be that we have to disassemble 44 American made in 1871. the gun in order to inspect and clean it properly. In either case, those screws and pins have to come out, and they will often be stuck fast by a coating of rust, along with old grease or oil that, over time, has hardened into a cement-like varnish.

We can also count on the screws being difficult to turn, because most gun screws were manufactured to very close tolerances, and the screw heads are often countersunk neatly into the side of the receiver. Those factors increase the surface area of the screw that is in contact with the firearm, offering a larger area that is subject to oxidation and, as a result, will offer even greater resistance to turning.

Something else to consider is that older factory-built guns were often manufactured by people who got paid by the amount of work they turned out in a day. Today, assemblers use a small airor electric-powered rotary driver set to a given torque to tighten the screws, but in the 19th century, the

bit and brace did the job the impact wrench does today. As you might imagine, it is easy to apply considerable torque to a screw using that U-shaped brace. The assembler’s primary concerns were to get the screws in quickly, and tightly enough that they would not loosen as the result of normal use. In all likelihood, he turned them in plenty tight. Some, in fact, were turned in so tightly that a little smidgen of rust or hardened oil will set them in place so firmly that they’re impossible to remove.

Forcing the issue will only result in tearing off the head of the screw, leaving you with the core of the screw still stuck in the gun. With old screws being such a problem, I’ll address this issue here in this article. Next month, in Part 2, I’ll cover dealing with stuck pins, separating wood from metal, and offer some hints on how to overcome the fact that each of us only has two hands. Safely Removing Old Screws Gun screws are turned by means of a slot that was machined into the screw’s head.

On all older firearms, these slots were simple and conventional—a rec-tangular slot running across the screw head, meant to accept a "straight" screwdriver blade. To remove the screw, we simply insert a driver into the slot and turn the screw out. That’s the theory, anyway. We’ll assume that the screw in question is very tight, so what we really need is a screwdriver blade that fills that slot completely and snugly. This is so we will be able to apply the maximum amount of turning torque to the fastener.

The slots in most gun screws were machined, so they are truly rectangular in shape. Even though we run into some with concave bottoms, the sides of the slot are machined straight, at 90-degree angles to the bottom of the screw head. Have a close look at a gun screw that is not installed in a gun, and you will see what I’m getting at. Now take a moment to look closely at a conventional, store-bought screwdriver blade, you can see that the driver’s blade is not straight-sided like a gun screw’s slot.

Instead, it is tapered. These kinds of drivers were intended to fit many different sizes of screws for general-purpose use around the home or repair shop, although it should be obvious that they won’t actually fit any screw slot perfectly. For gun work, we need a screwdriver with a blade that is known as "hollow ground." Like conventional screwdrivers, hollow-ground drivers also have blades that are tapered, except at the tip; the part that fits into the screw slot is ground so that it has flat sides.

Nevertheless, it’s not enough to simply obtain hollow-ground screwdrivers; we actually need to get drivers with blades of the correct size in both width and breadth, so they fit perfectly in the slot of the screw we want to turn. Since we will be exerting a good deal of torque on this blade, we don’t want it twisting out of the slot because its too thin, gouging the surrounding metal because its too wide, or distorting part of the slot because its too narrow.

Look over the fit of the screwdriver blade to the slot Figure 1. shown in Figure 1. This is a perfect fit in every way—the kind of fit we should have each and every time we turn a gun screw. Gun screws come in a variety of sizes, and many of the older ones are custom sizes, designed by the arms manufacturers to suit their own specialized needs. The fact that there are so many sizes has presented gunsmiths with challenges for years.

As a matter of course, whenever anew type of gun came in for repair, the smith would custom-grind the blade of a screwdriver (or drivers) to fit the screws in that weapon. Understandably, it didn’t take long for the working gunsmith to accumulate a massive selection of different sized drivers. Today, there are several makes of good-quality hollow-ground screwdrivers available for the gunsmith. Among the most well known are the type with a conventional fixed blade and serrated wooden handle.

Since my work consists primarily of work on older guns, you can understand why I used to own hundreds of screwdrivers like this one. A very different approach to driving screws is the one offered by Brownells with their brand name Magna-Tip screwdriver sets. The Magna-Tip system uses one handle, with several styles and sizes of handles available.

This basic handle is made with a 1/4-inch hex drive to accept a huge array of different sizes and shapes of hollow-ground straight bits, as well as conventional Phillips, Allen, and Torx style bits. For the working gunsmith or the advanced

INS02 At Last! Liability Insurance Ad (pickup from 5/02 issue)

Even the tightest screws can usually be removed with this tool. amateur, I believe the Brownells Magna-Tip drivers offer you the biggest bang for your buck, as well as the ability to fit the whole thing into a very small space on your workbench. I’ve been using these constantly since converting to this system over 15 years ago, and I’m convinced this is the single greatest set of tools ever invented for the gunsmith.

With a Magna-Tip screwdriver set like the one pictured on page 11, it becomes a fairly simple matter to select a bit that closely fits the screw slot for width, then you can run up the line of bits in that width and select the bit with the closest, tightest-fitting blade thickness. A good driver set like this will handle your needs for about 90 percent of the guns you will take in.

For the other 10 percent, standard-size Magna-Tip bits can be readily altered using a special grinding stone sold by Brownells for this purpose. So, you have the right screwdriver blade in the slot; it fits well from side to side; and the thickness is such that the driver has to be lightly tapped in. Good, that sounds like a perfect fit. But before we start turning the screw, there is another thing you should look at closely, and that is the slot itself.

Over the years, slots, especially the narrow ones, tend to fill up with accumulations of old oil, dirt, and rust. Such deposits are not only unsightly, they may prevent your "perfect-fitting" bit from fully entering the slot, meaning you may only have half the purchase you think you do. Spray some penetrating oil or cleaner into the screw slots and go in there after it with small dental picks. Scrape and scrub the slot until it is absolutely cleaned, all the way down to the bottom.

With the slot cleaned, the screwdriver bit will fit down into the slot like it should—all the way to the bottom. Take the time to notice the shape of the bottom of the slot. Is it flat or is it concave? If you want to get the maximum amount of bite on that screw, then you should grind the face of that blade to match that bottom contour as closely as you can. In this way, the bit will fit even farther down into the screw.

In practice, now that we have a driver blade that fits perfectly in the slot, and have cleaned the slot so the blade fits all the way down into it, we are ready to move forward in the attempt to turn that screw. With very few exceptions, most gun screws have right-hand threads. This means they turn in to the right, or clockwise. To unscrew them, they will have to be turned in a counter-clockwise direction. (The hammer screw used on the Colt Double Action Army Model of 1878 is one commonly found exception.

This is a left-hand thread and the screw must be turned clockwise in order to remove it.) So, assuming we know which direction to turn the screw, it’s also very important to hold the driver straight down into the screw slot, so that all of the torque you are applying doesn’t allow the blade to tilt sideways and slip up, out of the slot. Therefore, I like to think of this as a three-part operation.

The first one-third of the torque you are applying is for turning the screw; the second one-third is holding the driver straight and parallel with the screw; and the final one-third is pushing and holding the driver down hard into the slot. If the screw starts to turn—like it supposed to—we should be in good shape. But what if the screw doesn’t turn? Then we have to take some other steps. Simply pushing and turning harder on the screwdriver is not usually the answer.

Really stubborn screws can often be removed with greater safety by eliminating the reasons for the stubbornness before trying more force. As we already know, those reasons are usually rust and/or hardened lubricants. I like to start by trying some heat on the area around the screw and on the screw itself. Of course, this can only be attempted after removing any wood in the area of the screw.

I like to try heating the area up to about 250 to 300 degrees Fahrenheit, or just hot enough that a drop of water will "jump" back at you. This small amount of heat will not harm bluing or plating, but if the temperature is maintained for several minutes, it will begin to melt the old lubricants. You can try this in a home oven, but you should think about the possibility of contaminating it with the smell from the lubricants before you do.

Now, while the surface is still hot, apply some penetrating oil, followed again by a steady application of heat in order to try to maintain that 250- to 300-degree temperature. Be patient. After a bit, you should begin to notice tiny bubbles appearing around the seams at the screw head and threads. This is an indication of air and possibly old oils escaping from inside the hole.

If the area has been well covered with penetrating oil, the second you remove the heat source some of that hot penetrating oil will be pulled into the area between the screw and the gun. That hot oil will begin to dissolve the rust, and will mix with and dilute the old lubricants already there. Keep this up for five or 10 minutes, and then try to remove the screw once again while the whole thing is still hot.

Experience has shown that in most cases, the screw will begin to turn after this effort. (continued on page 21)

If it still refuses to turn, the next easy step is to try a tool called a "screwjack." A screwjack is a type of clamp with a hollow screw at its center that holds a Magna-Tip driver bit. The tool is basically bolted onto an area of the gun so that its hollow screw is centered over the stuck screw. A tight-fitting driver bit is installed into the hollow screw, which is tightened into the gun. All this is designed to hold the bit straight down into the screw slot as tightly as possible.

A 1/4-inch wrench is then used on the flats of the bit to turn the screw. The screwjack offers you the ability to exert a huge amount of torque and downward pressure directly into the screw, and in most cases, it will begin to turn right away. As the screw turns, you do have to slowly back out that hollow screw in the jack along with it, until it gets to the point where it can be turned with a screwdriver handle. Then you can remove the jack.

If the screw refused to budge, try the jack along with the heating procedure. There will always be that obstinate screw that still won’t budge. For these, there isn’t much left to try other than to drill them out—a touchy procedure that I’ll go into in a future article. Speaking of tight parts that are screwed in, removing the nipples from the cylinder of a percussion revolver can be a real chore.

Nipples are turned by means of a tool called a "nipple wrench." When the nipples are in so tight that you can’t budge them, try the same trick we used on the screws above; that is, heat and penetrating oil. You can also remove the nipple the way I do in my shop. I tightly chuck the nipple wrench in my drill press, place the cylinder on the drill press table under the wrench, and hold the wrench down tightly onto the nipple with the press. In this way, the wrench can’t slip up off the nipple while it’s being turned.

To prevent damage to either the cylinder or the nipples, this method requires a nipple wrench that fits the nipple very closely. If you use it along with the heat and penetrating oil, you should be able to remove most stuck nipples. Of course, that assumes that the nipples are still in good enough condition to be turned.

If they are so battered and ruined that the nipple wrench cannot grasp them, you may have to resort to much more complicated methods for removal. ■ ■ New Member ■ Membership Renewal These rates are good in U. S. and Canada only. For all other countries, annual dues are $60 payable in U. S. funds. 3. To Give a Gift Membership Enter your name and address above (in Section 1) and your giftee’s name and address below. The membership rates stated above apply to gifts. Name Street City State Zip