You walk into your local gun shop; or you’re strolling the tables at a gun show; or you’re perusing the gun auctions at an online auction site; or you’re out cruising the online store of a gun dealer; and you see it. The one. The military surplus firearm you’ve dreamed of for years. There it is, just waiting for you. Rational thought flees before the lust of acquisition, and soon you are the proud owner of your dream gun! Just one little problem. Your dream gun isn’t a gun yet. It’s a vaguely gun-shaped object buried under a layer of greasy preservative gunk known as Cosmoline. How are you going to get all that crud off your new toy? First, stop thinking of Cosmoline as gunk or crud. Cosmoline is your friend. It puts guns into suspended animation, so they come to you in good shape. But before we think about getting it off, let’s look at it so we can better understand the approaches that may be taken to remove it. Cosmoline is a "petrolatum-base corrosion preventative compound," to use the words of MIL-C-11796C, the US Government specification for Cosmoline. It’s a beefier cousin of Vaseline petroleum jelly. It comes in three classes. Class 3 is the variety used to preserve military small arms. American Cosmoline is specifically formulated not to stain the materials it is preserving. Its flash point, the temperature at which it will burn, is 350 degrees Fahrenheit. It melts at 135 degrees F. It penetrates permeable substances like wood to a depth of 0.2 to 0.25 millimeters. It is stable between a range of 255 degrees F. and –40 degrees F. It will protect anything coated with it indefinitely anywhere on the planet’s surface. That’s why military establishments around the world adopted it for preserving firearms. Exactly how the military used it varied from country to country, and by circumstances. The usual practice was to detail-strip and clean the gun, and then put it into a vat of liquefied Cosmoline. Some countries would just give it a quick dip in and out without even cleaning it first, such as the Soviet Union did to their battlefield pickup German Mausers when they were in a hurry. Others, like the various United States arsenals and arms depots, might put it in for a minute or so. One noted firearms writer (I can’t remember whom, it might have been Jeff Cooper or Elmer Keith) recounted a story from his time in the service about getting guns ready to be shipped to the South Pacific. They dropped them into a kettle of hot Cosmoline and left them in until air bubbles stopped coming up, then fished them out and put them in stands of arms for shipment. The longer the gun was in the Cosmoline, the more of it there will be to remove. There are essentially two approaches to removing Cosmoline from a firearm. One is by heat, melting it off (or driving it out, in the case of wood). The other by dissolving it with some sort of solvent (pulling it out, in the case of wood). Both methods are valid. Which to use depends on your circumstances, the rarity of the firearm, the overall condition of the firearm, and whether you intend it for display as a collectible or for use as a shooter. Regardless of which way you decide to go, the first step is to detail-strip the gun. Once that is done, you are ready to begin. Let’s look at the heat method first. The plus to this method is the temperature needed to melt Cosmoline is not terribly high, and you run little risk of damaging the finish on the wood. The minus, particularly with the wood, is it takes more than a little time to bleed it all out. I’ll come back to that point, but first let’s look at the metal parts. As the military specification notes, Class 3 Cosmoline will melt at 135 degrees Fahrenheit. However, you can’t just go to the kitchen faucet for your hot water. Most domestic hot water heaters are set to only 120 degrees F. and that’s not hot enough to do the job. Fill up the teakettle and some pots of water and heat them to boiling on the stove. Don’t forget your hot mitts or Nomex gloves so you don’t get scalded or burned! Cosmoline hit with boiling water melts like cotton candy and runs right off. I suggest using pans for cleaning the small parts; keep agitating them, and change the water as it cools. Some people add a little degreasing dishwashing detergent to the water, others don’t. It seems to be a matter of what works for you. (Note: don’t dump the used water down the drain unless you are prepared to clean out the pipes with drain cleaner immediately afterwards. Put it down the toilet instead; the pipes won’t be as affected by congealing grease.) Scrub them with a brass bristle ‘toothbrush’ until they are clean, then take them out of the water and set them out to dry. When dry, oil or grease them up as appropriate. Getting Cosmoline out of the barrel and the receiver is tedious but not hard. Put the receiver into a bucket or pan, put a funnel into the muzzle, and pour boiling water down it. As the barrel and receiver heat up, the preservative will flow out. Repeat as necessary until it’s all gone. Let the barreled receiver dry and cool down, then oil or grease it as indicated to prevent rust. Now you have the wooden parts to deal with. There are a couple of ways to go, depending on your patience, what you have available to work with, and the forbearance of your significant other. You choose. I’ve heard of people putting their stocks and forearms into the oven with the temperature set to its lowest setting, with a disposable turkey pan or sheets of aluminum foil bent into a crude catchbasin on the floor of the oven to catch the drips as the Cosmoline bleeds out of the wood and ‘cooking’ the wooden parts for an hour or two. I’ve heard of putting the stock into a black plastic garbage bag on sheets of newspaper and leaving it in the sun in a car or on the back porch in the summertime. The Cosmoline bleeds out and is absorbed by the newspaper. Change the newspaper and do it again. Repeat over the course of five days to a week, and 99% of it will be sweated out of the wood. I’ve heard of hanging the wood in the sun over a pan of cat litter and just leaving it there for a week – this seems to work best in the Southwest in high summer. I’ve even heard of people putting the wood into a dishwasher with dishwashing detergent after removing the to tray so it will fit and running it through on the hottest cycle the dishwasher has. (After removing the stock from the dishwasher, they immediately run the empty dishwasher with dishwashing detergent on the hot cycle again to be sure all the Cosmoline is gone and their wives or girlfriends won’t clobber them!) I’ve heard of using a good degreasing detergent and scrubbing the wood by hand. Any of these will work to remove the Cosmoline. The thing to remember is once the Cosmoline is out of the wood, you have to immediately take action to preserve the wood again. I’ll cover that point later on. Then there is the solvent method for dealing with Cosmoline. Cosmoline is a petroleum jelly variant, as noted earlier. It dissolves very nicely in mineral spirits, also known as paint thinner. The plus to this technique is its speed, particularly with small parts. The minus is mineral spirits can damage wooden parts and will take any finish like shellac right off the wood. If you go this route, take as a given you will have to refinish the stock and wooden parts of your firearm. Now we can proceed. Note: When you buy the mineral spirits, also buy an empty gallon paint can. You’ll need it for disposing of the used spirits later because you have to treat them like used motor oil or pesticides and dispose of them the same way. Put the small parts into a pan or pans. I find disposable baking pans you can get at a dollar store work well for this. Cover them with the mineral spirits and let them marinate for awhile. While they are soaking, you can start work on the barreled receiver. Put a plug in the chamber. A cork is fine, a whittled piece of wood will do; just something to make it more or less liquid-tight. Then fill the barrel with mineral spirits and let it soak. Put the receiver into another pan to catch any leakage. While you are soaking the barrel, go back and using brass bristle brushes, scrub all the small parts you've had soaking. After scrubbing, put them into a pan of clean mineral spirits to soak again and go back to the barreled receiver. Scrub down the barrel exterior and the receiver using brass bristle brushes and green nylon scrubbie pads until it’s clean. Dry off the mineral spirits so you can get a good grip on the assembly. For the next step, it’s helpful if you have a gun rest, a gun vise, or someone to help you out. Assemble your cleaning rod with the appropriate caliber brass brush on the end. Remove the plug in the chamber and let the liquid flow out. Put the barreled receiver into the vise and lock it down; or pin it into the gun rest with one hand; or have your assistant hold it firmly. Push the cleaning rod through, then pull it back. Repeat as necessary until the brush passes freely back and forth. If the firearm has been Cosmolined for a long time, this may take a few minutes. Turn the assembly around and change to a larger brass brush (for most military rifles, a 20-gauge shotgun brush works for this step) and repeat the process on the chamber. If you have a really gunked-up piece that does not want to pass the brush, there is a trick you can try. Lock your cleaning rod and brush into an electric drill and let the torque of the drill do the scrubbing for you. But save this trick for a last resort. Most cleaning rods will have a tendency to bend on you when you apply torque to them. You could damage the muzzle that way. Examine the chamber and the barrel with a bore light. When you’re satisfied you’ve cleaned all you will get with the brush, switch to patches soaked in thinner and scrub until they come back clean. Run through dry watches until they come back dry. Set aside the barreled receiver. Go back to your soaking parts and scrub them down with a paintbrush to get anything the brass bristle brush might have missed. Rinse them in the solvent again and set aside to dry. When all the metal parts are dry, lubricate them and set them aside. You now have to deal with the wood. Refer back to the earlier section on wood for additional information. As before, you have to decide if your firearm will be a collectible for display/investment, or a shooting arm. This determines how to approach the wood. If you are trying to preserve an existing finish, use something like diluted Murphy’s Oil Soap or degreasing dishwashing liquid in a little water to clean the Cosmoline off, with cloth as your scrubber. Get off as much as you can, and then use low heat either in the sun or an oven to bleed the rest out of the wood. If you don’t care about the finish, or plan to refinish the stock, go to town with the solvent and green nylon scrubbies and just scrub all the Cosmoline off. It will be the work of an hour or two to clean a rifle stock. When you are done, you may want to heat it a bit to make certain you’ve removed it all. Either way, the solvent and nylon will have raised the grain of the wood, and you will have to lightly sand it by hand with fine sandpaper before you refinish it. (I find I get good results with 400 wet-or-dry sandpaper.) Be careful as you work. You don’t want to obliterate any arsenal cartouches, inspector’s stamps or rack numbers. Another hour or two should see you ready to refinish. What finish should you use? Why are you asking me? It’s your firearm! Use what you prefer. I use tung oil varnish on my military firearms. It might not be authentic for all of them, but I like the mellow glow it gives the wood and I find it easy to touch up if I am sloppy while cleaning with Hoppe’s No. 9. There are folks who swear by Tru-Oil. Some purists go with a boiled linseed oil finish. A few go beyond that and use the hand-oil method, which essentially involves putting a dab of the appropriate oil on your palm and methodically rubbing it into the stock over and over and over again. Done for a long time, it gives the wood a warm glow and a hard finish. Some people use shellac after they sand. I know of one guy who uses lemon oil. I’ve even met one or two who use polyurethane. (Pardon me while I shudder.) As I said, it’s your firearm. Finish it to suit yourself and what you intend for it. When you have everything cleaned and refinished and lubricated, reassemble your firearm. I strongly suggest you either check the headspacing yourself, or have a gunsmith check it before you fire the piece. This is critical with bolt action rifles if you disassembled the bolt, which you almost certainly did in the course of cleaning it. Spending a few minutes and a couple of bucks now will save you lots of time and money later. When you are satisfied the action is in good working order, properly lubricated and ready to go, take your weapon to the range. At this point you are checking for function, not for accuracy. Load two, and only two, rounds of ammunition. Why two rounds? You want to see how your gun behaves. For example, semi-automatic firearms have been known to have worn trigger sears. When you retract the bolt and let it snap forward to bring a round into battery, what could happen is the bolt strips a round out of the magazine and rams it into the breech; the firing pin hits the primer and fires the round and then the bolt cycles and does it again, all without your touching the trigger. This is called a "slam-fire." It means your gun is defective and must go to the gunsmith for repairs. A bolt action might chamber and fire the first round okay, but not want to open and retract the spent case properly without needing great force to work the action. This is a condition known as "2x4 bolt" because you need a 2x4 to beat the bolt handle to make it cycle. It usually means either that there is more Cosmoline to be cleaned out; or that you have a seriously defective or misassembled bolt. Either way, you’ll want to strip and clean it and try again before going to the gunsmith. Other firearms can have other failings. Let’s not get into that now. Chances are, if you’ve done your job with due diligence and attention to detail your new gun will shoot just fine. Once you are sure of this, load up, let fly, and enjoy! Now, wasn’t it worth all the work and bother of cleaning all that beneficial Cosmoline away to get to your new friend?