[SIZE=7] Among Us Gaming's Guide to Stubborn Screw Removal[ /SIZE]
Introduction
For any of us who work on older guns, or guns that have seen a lot of service and not a lot of love, screws that don't want to come out are an ever-present problem. I see many discussions had on the topic, but very rarely does anyone know the full gamut of stuck screw removal. Few seem to know that there are many other options besides oil, heat, and pressure. While some of these methods may not be the most simple, and can cause damage if you're not careful, 99 times out of 100, one of them, or a combination thereof will remove that stubborn fastener. As we say in the mechanic industry: "out is out."
Preliminaries
Some things before I begin. These methods are not necessarily listed in a specific order, though they are listed in a gradual climb of time, effort, and resources needed, as well as the level of invasiveness of the procedure. It is important to remember as well, that caution and finesse must be used when applying heat, especially on places like receivers, bolts, and falling blocks that are heat treated. In all cases, finesse must be used at all times. It takes very little for a screwdriver to slip off the screw and gouge a stock. I also make no recommendations nor subscriptions to any particular tool described here. If brands are mentioned, it is because I personally use them and have familiarity thereof. Whenever the use of a screw-removing method or element is mentioned, it is said with the inherent application of immense downward force on the screw head. Furthermore, the later methods a said with the thought of oil and heat being used in conjunction with the given method. Additionally, this is a guide for rusted screws only. I have personally had great success with all the methods mentioned, and I have worked on some guns that were so rust that the trigger guards had portions of them completly rotted away. It is also important to remember that while tools can be replaced, 100 year old screws cannot. This is not to say that you cannot damage or destroy a screw when needed, but that it is better to sacrifice a tool than a screw.
Pre-removal Inspection Concerns
1. Make sure the screw is not staked, peened, locked, or has some other method of retention. You cannot remove these screws with any of the methods below without breaking them. Additionally, if you cannot replicate the screw on a lathe and perform the same mechanical retention to hold it afterwards, you do not need to be removing it. If it needs to be removed, take it to a qualified gunsmith to do it for you.
2. Make sure your stubborn screw is not under tension of any kind before you use any of the particularly invasive methods. A warped stock can put a lot of tension on a screw and make it refuse to come easily, and there is no reason to apply heat or excessive oil if that is the case.
3. Make sure the screw is indeed straight and with clean threads. If your screw is bent, there is a good chance it will not come out at all, and will have to be cut. Trying to remove a bent screw will damage the threads and scar up the surrounding area.
4. Make sure your screw does not posess any chemical retention, I.E. Loctite. If it has chemcial retention, heat is required on the area the threads are in, which will soften the chemical and allow for easier removal.
Methods
Of course, the first, and most simple and easy of methods is your generic home screwdriver. As long as the tip is not twisted and fits the slot well enough, you should not have any issues.
If that does not work
Move to a screwdriver with a tip that fits the slot very well in length and width. This is where you would want what is called a "Hollow Ground" screwdriver tip, which is a tip ground in such a way that it meets an exact scrwedriver slot dimmension. You can get screwdrivers like this, or what I reccommend is to get a screwdriver set with a bunch of hollow ground bits, as that allows you far more options.
If that does not work
Apply a penetrating oil of your choice, and allow to soak for an hour minimum, checking up on it every so often to add more if needed. I generally advise against WD40, as it is not actually a penetrating oil and other oils will serve you better. Be careful, as penetrating oils have rust dissolving properties, and if your gun is rust blued and you are not careful, you can strip off said blueing.
If that does not work
Then now it is the time for heat. ONLY USE PROPANE. You do not need MAP gas, or heaven forbid oxy acetylene. Do not hold the torch right against the metal, but hold it a few inches away. You only want to heat the work up enough that the oil begins to smoke. At this point, turn the torch off, and apply a penetrating oil. The idea is twofold. Firstly, the expansion and contraction of the metal from the heat will help break the rust. Second, it allows the spaces between the screw and whatever its holding to suck the oil in via capillary action. You may need to do this several times before it works and the screw comes out.
If that does not work
Get a 1/4" ratchet with a 1/4" socket, and put your bit in it. With this method you MUST make sure you are holding the rathcet paralell to the screwhead exactly. If you do not, you will cam out of the screwhead, and strip it further. The ratchet allows you far greater torque than you can acheive with a regular screwdriver. If you have a large enough vice, you can put both the tool and the gun in it, and clamp with mild pressure. This does 2 things: it keeps the work and tool parallel (and if it does not due to the geometry of the gun, you can shim the gun to be parallel), and provides an immovable force against the tool and gun, such that the screwdriver bit cannot cam out. This can lead to the bit snapping, or the screw head being wiped, but that is where finnesse comes in.
If that does not work.
You may want to try an impact driver. Tool note: an impact driver is an impacting tool that accepts bits as its primary tool. If your tool has a socket drive on it, that is an impact wrench and should not be used. I reccommend the impact driver hesitantly. In my experience they jump around too much to be consistently effective, and because of that have a tendency to damage surrounding metal and wood, and destroy screw slots. That said, I have found them to be useful on stubborn wood screws, and can reccommend them for that purpose.
If that does not work
Now is the time for a hand impact driver. Where the tool above is an electrically powered impacting gun, the hand impact functions in a different manner. It is a hand sized milled tube with a vertical cam and spring in it, with a drive end. When you hit the top if it with a hammer, the tube comes down, acting on the internal cam, and rotating the drive end. Though they mostly see used in the automotive industry for stuck brake rotor screws, I have had success with them on guns as well. To use one, first check that it will move in a loosening direction. Then insert the right sized bit, and postion it on top of the screw. Then apply mild pressure to turn the tool in the loosening direction, and hit the top with a hammer, softly at first, but harder if need be. Make sure that the gun is held very firmly in a vice, and that your mild pressure in the direction of lossening is firm. This way, when you hit the tool with a hammer, most of the applied torque is transferred into the screw, instead of rotating your hand or the gun
If that doesn't work
Then now is time for the air hammer. You of course, get your air hammer and neccesary equipment to run it. You then need to get an air hammer bit driver/socket adapter bit for it. Install that, and get your appropriate bit installed. Hold the gun very firmly in a vice, postion the airhammer assembly parallel, grab the adapter bit handle and pull it in the loosening direction, and apply a little trigger pressure, and more as needed, until the screw comes loose. Be exceedingly careful with this method, as you can very easily split screwheads, or peen screws into place if you're not careful. This method is highly effective, but should be a total last resort, as severe damage can be caused if you're not careful.
If that doesn't work
That's it. If none of these things have removed that screw, you've either done something wrong, or you will need to drill out that screw to remove it.
Thoughts and Advice
Stuck screws can be pretty ugly. The methods above are everything I've tried on some really nasty stuff (If you're considering one of the Ishapore .410 Enfields on centerfire systems or form Hunter's lodge, don't unless you want to go through all these steps), and they all brought success in one way or another. Hollow ground screwdriver bits really are a screw saver, and are absolutley worth the purchase. I use a set off brownells, but any gunsmith set will do generally. As for penetrating oil, I am a PB Blaster guy, as it seems to work very well, and is a heck of a lot cheaper than kroil, though kroil is still plenty good. If any questions are had feel free to ask.
