Oiling cartridges


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Macpherson
January 22, 2008, 01:25 AM
I currently have a Yugo SKS that does NOT like Wolf steel cased ammunition. It consistently fails to eject the spend cases and usually requires some yanking on the bolt to get the case out...occasionally requiring a serious whack or two to get the darn thing open again. (I have cleaned the chamber extensively and replaced the gas valve, so I don't think it's a problem with the gas system.)
I tried using some brass ammunition and it cycled almost flawlessly, so my theory is that the steel cases are seizing in the chamber while the smoother and softer brass cases slide out and are ejected more readily. It was suggested to me by a friend that I try using some motor oil to lightly oil the steel cases prior to firing, to add "slipperyness" to them. Has anyone else heard of this idea, and if so is there any problem with using plain motor oil or should something else be used (i.e gun oil)?

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HOLY DIVER
January 22, 2008, 01:31 AM
brass fires allmost flawlessly?every sks i ever fired would chew up and spit out steel cased ammo with no prob......i'm no gunsmith....but i'd take your rifle to one

Float Pilot
January 22, 2008, 01:43 AM
Oiling the case of a rifle cartridge is a good way to get hurt. When any rifle fires the case expands for a micro second and adheres to the walls of the chamber. Then it springs back and can be ejected. This seals the gases on the right side of things and makes sure your headspace is not changing during the firing process.

Smokey Joe
January 22, 2008, 01:44 AM
Macpherson--When a cartridge gun is fired, the chamber pressure forces the sides of the cartridge against the walls of the chamber, sealing the gases in. If the cartridge is lubed, the cartridge just slips to the rear, putting all the pressure of the firing on the bolt face.

This is not a good thing to do to a bolt face. The gases may be able to escape and come rearward (toward YOUR face!), or the bolt may seal the chamber, but at the cost of enduring more wear and tear from the high pressure.

That's why it is NEVER a good idea to allow any oil or grease in the chamber of a firearm.

I agree w/000Buckshot--An SKS that won't happily shoot steel-cased ammo--as well as brass--all day long has a real problem. They were designed to shoot steel-cased ammo. Get ye to a gunsmith with the SKS pronto.

And please give us a report on what he says.

Rshooter
January 22, 2008, 02:01 AM
Greasing of rounds has a interesting history and is blamed for some of the bursting of 1903 chambers. Bad idea. It is blamed for not letting the casing expand and seal the chamber allowing some of the cup pressure to exit back against the bolt. :eek:

http://www.odcmp.org/1101/can.pdf

dmftoy1
January 22, 2008, 06:47 AM
I think if it was me I'd probably give the chamber a good thorough cleaning before taking it to a gunsmith to see if that fixes your problem. I've had some of that steel cased stuff leave nasty deposits in the chamber and I'm betting that it's just sticking to the steel more than the brass.

Just my .02

Regards,
Dave

Waywatcher
January 22, 2008, 06:51 AM
Clean the crap out of your chamber.

Swampy
January 22, 2008, 07:59 AM
Macpherson,

Oiling cartridges is very bad ju-ju.... both for the firearm and possibly for you as well.

One word....... Don't.

Swampy

Bottom Gun
January 22, 2008, 09:07 AM
One more vote for cleaning the chamber.

ID_shooting
January 22, 2008, 09:41 AM
Here is why everyone is saying to clean the chamber...

Some com-block ammo has a lacquer coating. As the rifle heats up, the coating becomes soft and rubs off in the chamber. After several hundred rounds, it will leave a fine coating over the entire chamber. Now, when the rifle cools back down, the coating hardens. This does two things. Makes the chamber slightly smaller and leave a sticky film that is very hard to get out. Brass will still function because it is flexible enough to cycle through. Steel will have a much harder time because it doesn’t flex as much and is coated. You actually have the coating on the case bond to the coating in the chamber and this is why you have to pound the bolt open. If it was a faulty valve, the bolt would open as normal when you manually actuate it.

Now, what to do about it? Since you mentioned a gas valve, I will say you are using a Yugo SKS. This rifle should not have a chrome bore and thus you have to be a bit more careful. You have two methods, heat or chemical.

You can heat the rifle up by firing then immediately pull the dust cover and bolt assy and hit the chamber with an oil soaked chamber brush and clean thoroughly. Then dry the bore, reassemble and all should be fine. FYI, some ranges will object to you cleaning while on the firing line.

The other is to use a very strong solvent to remove the coating. Clean like normal, and spend lots of time in the chamber. Use a good bore light, the bore should end up a bright polished silver color. If it has a green or brown tint, there is still lacquer on it. Once clean, lightly oil the chamber and bore, let soak and then wipe excess oil out.

Try this and let us know how it goes.

Full Clip
January 22, 2008, 10:52 AM
I will say he's got a Yugo because he says "I currently have a Yugo SKS that does NOT like Wolf steel cased ammunition."

Get out a bore light and check not only for goopy buildup but for any possible burrs that may be hanging up the steel cases. Inspect your brass as well for any odd expansion or other marks.

Bwana John
January 22, 2008, 12:16 PM
I was very suprised at MG shoots to see shooters lubing whole belts for crew served weapons.

The MGs did run better when the ammo was lubed, but I didnt like the idea.

Gewehr98
January 22, 2008, 02:04 PM
As a matter of fact, many machine gun designs had integral cartridge oilers, aiding in feeding and extraction of rounds in combat conditions. Google the Hotchkiss and Breda, among others.

They were also designed to handle the extra bolt thrust of oiled ammunition.

Bottom line: Good for machine guns, bad for Yugo SKS and other rifles not designed for that application. ;)

Macpherson
January 22, 2008, 02:31 PM
Many thanks for the replies all, I will not proceed further down the cartridge-oiling path. I had heard of this being done with machine guns but didn't realize that it could have vastly different results in a rifle :what:

A dirty chamber was the first thing I suspected as well, so I cleaned the bore as well as I thought possible, to include using carb cleaner and several bore cleaners in succession combined with attaching a bore brush to a cordless drill and letting it spin in the chamber for several seconds. Even after all that the chamber is still not very shiny, so I will try cleaning the chamber while it's hot next time.

I had noticed some scratches and dents on the empty cases on occasion, but I didn't have the presence of mind to save any. Weather permitting I will take it shooting again this weekend and report back with results.

Cosmoline
January 22, 2008, 03:24 PM
Oiling cartridges? No way! Your SKS is the problem. My guess is there's a burr or a warble in there that's catching on the steel cases. Clean the chamber really really well and if it still refuses to functoin with wolf you can take it to a gunsmith or just use brass cases. A properly functioning and cleaned SKS should not have this problem though.

rcmodel
January 22, 2008, 03:32 PM
Good for machine guns,Good for machineguns designed 75 - 100 years ago.
Not so much anymore though!

Just don't do it!

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

NORTEXED
January 22, 2008, 03:42 PM
Try some brake cleaner on the patch to remove residue, and as a last resort, mark a cleaning rod at a depth from the chamber that is at or almost at the neck, wrap some 0000 steel wool around the end of the cleaning rod and spin slowly with a variable speed drill to just polish the chamber. Clean well again, oily patch it then dry patch it a couple of times.

briansmithwins
January 22, 2008, 04:25 PM
Something is wrong with the SKS. I would suspect a bad chamber.

A smith can make a cast of it to check, or look for a repeating defect in fired cases.

The French AA-52 machinegun also likes oiled or greased cartridges, but then again it's blowback operated. BSW

LeibstandarteAdH
January 22, 2008, 04:55 PM
to help things out:
Try some brake cleaner on the patch to remove residue, and as a last resort, mark a cleaning rod at a depth from the chamber that is at or almost at the neck, wrap some 0000 steel wool around the end of the cleaning rod and spin slowly with a variable speed drill to just polish the chamber. Clean well again, oily patch it then dry patch it a couple of times.

Also, on an action and a round like that a little oil wont hurt, i have used that trick on a WASR-2 in 5.45x39.5 with good results for the same problem described, excessive cartridge friction leading to jams, that is just a crutch for a REAL PROBLEM Though.

Id be willing to bet your rifle is not all matching. You have a leakey gas system, and most liely, a gas tube that it too short, or the distance it has to cover to be "tight" is too long, one or the other. Ive seen it a hundred times with mismatched SKS's at InterOrdnance

Bad Penny 03
January 23, 2008, 03:05 AM
Too much oil, in the wrong places, tends to heat up and find its way onto the shooter in one way or another.
Aside from all the issues mentioned, hot oil spraying on you probably isn't a good thing.
When I was in my early 20's I fired a 1911 I had just taken out of storage and cleaned. I neglected to clean the very light coating of oil out of the bore and chamber I had put on with a patch (2 or 3 drops on a patch, not much) before storage.
After firing a few rounds through it on the first magazine I had an oily case eject, hit the wall, and go down my shirt...it stuck to the skin and sizzled. I instinctively tugged at my shirt to knock it out, I figured it fell out as usual... but what I didn't realize is that it had stuck. The pain increased...I put my weapon down...pulled my collar down and tore the case off my chest. I have a little triangular scar there now to remind me to keep the bore ( and ammo) bone dry...even a slight amount of oil were it doesn't belong can be painful.

Snapping Twig
January 23, 2008, 03:20 AM
Oil and primers is a bad idea.

Smith
January 23, 2008, 03:33 AM
My Yugo 59/66 SKS had trouble ejecting any ammo I put through it. If I remember correctly, all the brands I tried (Wolf, Sellier & Bellot, ChinaSomething) had steel casing. Turned out that the problem was the gas valve. It was pretty corroded and had lots of crud built up in it. Too much gas was escaping, resulting in not enough pressure to fully eject the shells. I ordered a new valve and swapped the old one out and I haven't had a problem since. I don't know if you have the same problem, but it's a possibility.

SlamFire1
January 23, 2008, 12:10 PM
“It was suggested to me by a friend that I try using some motor oil to lightly oil the steel cases prior to firing, to add "slipperyness" to them. Has anyone else heard of this idea, and if so is there any problem with using plain motor oil or should something else be used (i.e gun oil)?”

What you are experiencing is an example of excessive breech friction. Without a doubt the steel on steel contact between the case and the chamber has created so much friction that the mechanism is unable to extract the cartridge.

It is hard to say why. Steel cases different in hardness and temper, and dimensions. With a hard material like steel, your mechanism can’t swage the cases down as easily as a brass case. So maybe you have an interference fit leading to excessive breech friction.

There are good reasons why brass is the preferred cartridge material. Brass will will contract more on firing than steel, while I have not looked this up, I believe that frictional forces between brass and steel are less than steel on steel, and brass is harder to corrode. It is also a lot easier to manufacture brass cases than steel. Making steel cases is difficult, and if the temper or the material is a little off, you get extraction problems.

Adding a lubricant into the system will reduce the friction between the case and the chamber walls. This reduction may be enough to allow your rifle to function. Try putting an oily patch in a bag, add cases, and shake. Motor oil would be fine. You do not need much oil, ( I really doubt you need a film thickness greater than .001”) for this to work. The surface only needs a thin, definitely not dripping, coating of oil.


When a cartridge gun is fired, the chamber pressure forces the sides of the cartridge against the walls of the chamber, sealing the gases in. If the cartridge is lubed, the cartridge just slips to the rear, putting all the pressure of the firing on the bolt face.

This is not a good thing to do to a bolt face. The gases may be able to escape and come rearward (toward YOUR face!), or the bolt may seal the chamber, but at the cost of enduring more wear and tear from the high pressure.


As a matter of fact, many machine gun designs had integral cartridge oilers, aiding in feeding and extraction of rounds in combat conditions. Google the Hotchkiss and Breda, among others.

They were also designed to handle the extra bolt thrust of oiled ammunition.

Bottom line: Good for machine guns, bad for Yugo SKS and other rifles not designed for that application.

Gentlemen: Lubricated cases, whether oiled, waxed, lacquered, or covered in water, will seal the bore. I was surprised to find out that a case can have a lot of lubricant and the weapon will still function. I have used RCBS water soluble case lube, Johnson paste wax, and Stick Wax. No gas blow back, no excessive pressure indications. If you had seen the gobs and film thicknesses of Stick Wax I had on CAVIM 308 ammo, with perfect functioning, I doubt you would believe that gas blow back is likely. I do not recommend using Stick Wax, the stuff is very difficult to clean off the rifle, cases, and the human. The stuff went everywhere! But it was something I tried in a FN/FAL.

If you examine the literature on the design of semiautomatic weapons you will see that case friction is not taken into account for bolt loading. The bolt is designed to take the full load of combustion. The only dispute is whether the load is based on the outside of the case head, or the inside of the casehead.

What is totally true is that a lubricated case will transmit more load to the bolt than a dry case in a dry chamber. There is unfortunately a lot of friction between case walls and the chamber walls.

I say unfortunate because breech friction is bad. Breech friction means the designer has to use extra energy to peel that case out of the chamber. That means more gas venting, heavier operating rods, heavier extractors, etc. Life would be so much easier if cases were frictionless. All you would have to do is use your little pinky to open the mechanism and the case would fall out.

The reason you don’t see oiler and lubers anymore is that they are just another thing to go wrong. Early designs needed these contraptions, later designers figured out how to get decent primary extraction without them.

If however you are using overpressure ammunition you already have a problem. Lubricating overpressure cases will encroach even more on the design margins of any mechanism. So, don’t load overpressure ammunition and never lubricate the stuff.

LeibstandarteAdH
January 23, 2008, 03:44 PM
If it was a faulty valve, the bolt would open as normal when you manually actuate it

Yes, but the design leaves room (when functioning correctly that is) for such 'adverse conditions' as mere steel cased ammo to not render the chamber of an SKS inoperable. I think many people if not entire soviet block armys coult attest to something along such lines.

The gas system usually has a margin able to extract something that would be a little hard for you to open the bolt on with a strait pull not designed to be operated as such like a faulty SKS. Most will rip extractor sized chunks out of case heads, or rip them off entirely when a case sticks. With a propperly functioning gas system the ammount of sticking your noticing by opening the bolt with your hand would most likely never be percieved.

BorisDaBastid
January 23, 2008, 03:57 PM
"I was very suprised at MG shoots to see shooters lubing whole belts for crew served weapons.

The MGs did run better when the ammo was lubed, but I didnt like the idea."

Wowzers! that's insane! I always dump a boat-load of CLP on our 240C before we go out to a range or in sector to make sure it fires well, but always leave the ammo dry.

Honestly, if it's causing you so much trouble, and brass feeds fine, why not just stop using the steel cased stuff?

MudPuppy
January 23, 2008, 06:37 PM
Steel case stuff is soooo much cheaper.

I'd also look beyond the chamber, tear it down and get all the cosmo outta everywhere it tends to hide.

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