Buying Milsurp: Removing Cosmoline from the SKS

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Buying Milsurp: Removing Cosmoline from the SKS

October 18th, 2021

7:13 runtime

Ever cleaned the cosmoline out of an SKS rifle? In today’s article, we demonstrate a straightforward way of cleaning up a Type 56 carbine and simplifying the cosmoline removal process.

As a lover of guns, I aspire to collect pretty much all of them. But I remember a not-so-distant past where I looked down on “old” military surplus (or “milsurp” as they are often known) guns. After all, what purpose would some old beat-up war rifle serve in a self-defense situation in modern America? So guns like the Mosin-Nagant rifle and under-appreciated SKS never really appealed to me.

Chinese SKS after cosmoline removal
Getting all of the cosmoline off of your SKS can be a tough job, but the end result is definitely worth the time and work.

But somewhere along the way, my better sense took over and I began to appreciate the history and charm of these “old” rifles. And while the milsurp market is not what it used to be, I soon found myself eyeing an SKS rifle I saw for sale. To be honest, I think I almost loved the challenge of cleaning and restoring the SKS more than the SKS itself. The challenge I’m referring to is what I call the “milsurp experience”.

A Long Road

The milsurp experience is getting in a gun like the SKS that has been used by a military and then was boxed up in storage, usually in large wooden crates, and the guns are dipped in a preservative called cosmoline.

SKS covered in cosmoline
This gooey grease-like substance called cosmoline preserves milsurp guns, like this SKS, for decades and in all kinds of environments.

If you ask me, cosmoline is the grossest-feeling substance on planet earth. If you’ve ever picked up a gun covered in it, you know the struggle. Its thick, sticky feeling seems to come off on your hands but never actually comes off the rifle, somehow. It’s truly an enigma.

So, the obvious goals of acquiring a military surplus gun are cleaning the rifle up, getting it to function, and seeing if your gun has any cool or rare historical value. Removing all of that cosmoline is the first chore to accomplish. It might just be the hardest challenge to returning the gun to a useable state.

Cosmoline Removal: Step-by-Step

If you do it right, however, removing cosmoline preservatives can be easier than expected. Here’s how I did it.

Field stripping an SKS to remove cosmoline
Disassemble the SKS all the way down to clean it properly. Residual cosmoline can cause malfunctions or damage to the gun and shooter.

First, get all the materials: paper towels or old rags, cotton swabs, a spray bottle, odorless mineral spirits, gloves for working with chemicals, a pan, a garbage sack and, if it’s 100 degrees Fahrenheit outside and you are cleaning up your gun in the garage like me, then you will want a big bottle of water to stay hydrated. Trust me.

Using mineral spirits to clean cosmoline from a milsurp rifle
Mineral spirits strip away cosmoline from milsurp rifles. In the author’s experience, mineral spirits do not damage the wooden stock or gun.

Next, fill the spray bottle with the mineral spirits and start spraying down the rifle and wipe off all the easily removed cosmoline. Don’t spend too much time wiping it down, just remove the globs of surface accumulation. There will be plenty of time to detail clean later, believe me.

Once the first wipe down is complete, disassemble the rifle. Fortunately, the SKS isn’t hard to tear down. The cosmoline will be in all the joints and cracks, so pushing pins out might be harder than normal. Just make sure to align your punches correctly and use tape, towels or other buffers to prevent surface damage to the gun.

Disassemble the bolt, remove the magazine assembly, pull the trigger group, pop off the gas tube assembly and remove the bayonet. You want to get all of the small parts off and separated for cleaning. You can take notes and photograph everything during disassembly to help you reassemble everything later.

Cleaning the SKS bolt and firing pin
The firing pin channel and firing pin should be made perfectly clean.

Now it’s time to clean. Take all the little parts like the trigger group, bolt and firing pin and place them in a pan filled with mineral spirits. For maximum effectiveness, leave them to soak overnight. Cleaning these parts will be a chore, so it’s good to loosen up the cosmoline and give yourself a break.

The wooden stock can be placed in a trash bag and stored somewhere hot. Doing this allows the wood to sweat all the cosmoline out of it. I placed mine inside my storage shed, which on a summer day will bake anything placed inside it. I left this until I was ready to assemble the SKS, which would be the next day.

Removing cosmoline from wooden gun stock
The author placed the wooden stock inside a garbage bag and stored it in a hot place to let the wood excrete any embedded cosmoline.

With the stock sweating and small internals soaking, it was time to clean as much as I could. I wiped down the receiver, barrel, bayonet, the easy-to-clean surfaces of the bolt, dust cover and magazine with paper towels while spraying mineral spirits on each part. The mineral spirits caused the easy surface cosmoline to wipe right off the gun. I cleaned the bulk of the easily reached areas and started cleaning again in the morning.

Detailed SKS Cleaning

Now it was on to the detailed cleaning. Break out the cotton swabs and the SKS cleaning rod. I used q-tips to clean all the nooks and crannies. I got paper towels wet with mineral spirits and shoved them down in the barrel and then rammed them all the way through with the cleaning rod. It took doing this quite a few times to get the cosmoline from the barrel. I did this until the paper towels came out clean.

Cleaning the SKS rear sight
Removing cosmoline from areas like the rear sight can prove troublesome. The author recommends an ample amount of mineral spirits.

Really make sure to clean the cosmoline out of all the internals, the most important ones being the bore and the recess for the firing pin. The area where the firing pin sits has to be perfectly clean. If the area is not clean, it can cause an SKS firing pin to sit forward, which would not be good. I used cotton swabs to scrub this area and the entire bolt.

If you think you got it cleaned well, insert the firing pin back in its position and see if it will rotate with ease. If it does, then it means you got the bolt good and clean.

Last, I revisited the stock, wiped off the cosmoline easily with mineral spirits, and cleaned the details on the small internal pieces that had been soaking in the pan.

Proper lubrication of the Type 56 SKS
When reassembling the SKS, proper lubrication is important. For this task, the author opted for the tried and true Hoppe’s lubricants.

Now, it’s time to lubricate and reassemble. With the cosmoline out of the bore, I used a solvent to clean the barrel with a bore snake and a brush to be doubly sure she was nice and clean.


I enjoy the milsurp experience, and it definitely gives you a bond with the gun. In the future, I think the milsurp experience will be something I’ll enjoy sharing with my son one day. It is definitely something every gun enthusiast needs to experience since it can teach you about the gun, its history and also give you a newfound appreciation for firearms.

Finished SKS after cleaning and cosmoline removal
While the stripping of cosmoline from a milsurp rifle can be tedious, it is well worth the effort.

One of the keys to collecting milsurp rifles like the SKS is finding an efficient way to clean off all of that cosmoline. I hope this video and article will help you develop a method that works easily for you.

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