I was frying up some eggs for my breakfast this morning.

[Frohickey]

Vern Humphrey

The purpose of the cartridge case is to provide rearward obduration. it must "stick" to the chamber walls to do that, otherwise, you'll get high-pressure gas squirting back into the action (and into the shooter's face.)

A secondary problem is that the case reduces thrust on the bolt/breech block face at a cricical point -- the pressure peak. By gripping the wall of the chamber, it spreads that thrust over a wider area, and makes autos and semi-autos function more "gently."

There are some weapons that require lubricated cases, and those weapons must have special features designed in to prevent the resulting violent action from damaging the weapon in short order.

Lubricating cases is NOT a good idea, and I don't recommend anyone try it.

I disagree. The case head/bolt face combination is supposed to contain the rearward thrust of the firing of the bullet. If you need to have the cartridge case wall contain these forces, it would need be as thick as the case head. Besides, the direction of forces, and the angle of the chamber walls is not correct in order to 'stick' to the chamber walls. Its angled towards the bore, and not away from the bore. (If its angled away from the bore, you wouldn't be able to chamber it from the rear, you would have to 'chamber' the round from the side, with a split chamber.)

I agree. Lubing cases is NOT a good idea, at least prior to firing. Lubing cases prior to resizing is a different story.

 

[Vern Humphrey]

Quote:
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I disagree. The case head/bolt face combination is supposed to contain the rearward thrust of the firing of the bullet. If you need to have the cartridge case wall contain these forces, it would need be as thick as the case head.
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Try firing a few hundred well-lubricated cartridges and get back to me on it.

The case walls DO take much of the thrust -- that's why you get case head failures with excessive head space -- which isn't a failure of the head, but a blowout of the walls above the web -- the case is stretched backward to contact the breech block while tightly gripping the chamber walls.

A lubricated case will greatly increase bolt thrust, and in automatic and semi-automatic weapons will make the weapon function more violently, stressing parts.

Another example is the Lee Enfield. When it was used for serious target work in Commonwealth Armies, knowledgeable shooters would carefully de-grease the chamber before each string -- because of the effect of back thrust in a lubricated chamber.

 

[George Hill]

Sorry guys. The Honda car was like 18 years ago.
The polaroids I had were actually Kodak Instamatic pictures. Before Polaroid sued the crap out of them to get them to stop.

 

[shep854]

Regarding coating of chambers; isn't that one of the reasons for chrome-lining chambers and bores?

 

[horge]

Nice idea, Mr. Hill.

Can I offer a sidestep?

Why not include a dry lubricant in the propellant, something resistant to combustion (Teflon was mentioned) to be deposited as residue --this would make for a self-lubricating firearm, The lubricating residue would inevitably coat the chamber itself --albeit temporarily.

Dunno if this is already done, and...
Of course this may make bullet seating at the cartridge factory a little tricky.

 

[George Hill]

Maybe a Tungsten Disulfide coating on the brass.

 

[mnrivrat]

WOW !

I would put a "don't try this at home" disclaimer on some of these idea's.

It's always good to think outside the box when developing new things, but be careful what you TRY fellows .

The case normaly expands and grabs the chamber walls for both sealing the high pressures created by the controled explosion , and as I seem to recall it is also nessesary for helping reduce the pressure on the action .

Think long and hard and do some research before you put your new designs into action.

 

[WhoKnowsWho]

Has anyone tried e-mailing the ammo manufacturers and asking them directly?

 

[c_yeager]

All i know is that my momma almost smacked me upside the head for using an aluminum spatula on one of her nice teflon pans. Doesnt strike me as a material that would hold up to that much abuse.

 

[cracked butt]

A teflon line aluminum pan doesn't do anything a well seasoned cast iron pan can't do, and the cast iron pan can last lifetimes if taken care of properly.

If a cast iron pan is negelcted or abused, it can lose its seasoning or become pitted causing failure to extract or dificult extraction issues with your eggs.

 

[cracked butt]

Also-

too much lube or lube in the wrong spot can dent or buckle your brass in a sizing die, imagine what it will do in a chamber when fired.

 

[Azrael256]

Maybe I'm imagining things, or maybe I'm actually still in bed asleep, and this is an extraordinarily vivid dream, but I seem to recall that Remington Golden Bullet .22 ammo had a dry lubricant of some kind. I don't remember being able to feel it on the shell, but I think I saw it on the box.

George, I don't know anything about tungsten disulfide, but I do see the word "tungsten" and the first thing I think is "harder than steel." I don't think you'd want any kind of lubricant that is harder than the chamber. Each round would be part of a slow and dangerous sanding process that I wouldn't want to experiment with.

 

[Mikul]

One of the big IPSC shooters wipes down each round with moly before going to a match.

 

[George Hill]

I had an email suggesting the lubricating solution go in like a brass tumbler in the same way you use the tubler to coat bullets with moly.
You don't want to do this because there are places that you don't want them to be slick.
You don't want inside the case mouth to be slick and you dont want the rim to be slick either. Bullet setback is not a good thing and an extractor slipping off the rim is what we are trying to avoid.
Guys, and this isn't a Lube. There are no drops of oil... that's not what I'm talking about.
Yes, Wolf cases are coated to protect them from errosion AND to make them able to be extracted. 2 birds with one stone kinda thing.
It doesn't have to be a thick coating on the case... like Rhino Lining or something. And it doesn't have to be Teflon - that just gave me the idea.
But an electobonded powdercoat type that's only a few molecules thick will both make the case slick for improved feeding and extractions.

You see, the oversixed extractors are not solving the problem. The problem is sticking cases. The oversized extractor just helps get out the sticking cases. This idea keeps the cases from sticking in the first place. That's what this is about. Ive had in some rifles sticking cases. Even when the chamber was in good condition. Not all chambers are chrome lined. If they were, maybe we wouldn't need oversized extractors.
JD Jones pointed out to me another problem... increased cycle speed:

There are two major factory if "slippery" cartridge cases are used in semi-auto pistols. One --cost of application. Two--if it is really slippery the guns will operate at a faster slide velocity than designed. Try liberally oiling cases sometime--it usually makes a very noticeable difference. Like you I am unimpressed with most of the "Magic" in advertising. JD

You guys know who JD Jones is? He's right. The cost is the problem. The idea does work, but it would add about 2 bucks per box of ammo, and that's why they are not doing it. Increased cycle speed can be issue to some.... Don't think a Springfield '03 would be bothered. Maybe an AR might be.

 

[Frohickey]

Cal 30MG Malfunctions
Grease or heavy oil in the chamber invariably produces a flute in the fired case (fig. 30). Note the characteristically elongated and radially contoured shape of these flutes. Case heads will show some indications of high pressure. Figure 30 also shows damage to the gun which commonly results from firing with grease in both the chamber and the breech end of the bore. The high pressure ruptures the case head, releasing the powder gases into the action. Note the fractured "T" slot, cracked barrel extension, and bent cover.

Okay, if Varmint Al is around in THR, I would like to thank him for his analytical mind.
Here is his FEA of a Rifle Chamber Surface finish and its affect on brass cartridge case stretching and bolt face loading.

 

[stevelyn]

If you are experiencing extraction problems, the issue is most likely with the chamber rather than the ammo. You should probably take the gun to a smith and have him polish the chamber.
On firing, brass expands creating a temporary gasket sealing in the gases and allowing them to escape down the barrel behind the bullet. When the pressure drops, the brass relaxes due to its elasticity allowing the extractor to withdraw it from the chamber during the ejection process. Nickle plating on cases helps a little with feeding and extraction reliability, without compromising its sealing characteristics. Using anything else would over lube the case and defeat its gas sealing ability.

 

[entropy]

Unless you are firing a Breda or Hotchkiss GPMG/HMG, it is not advisable to lubricate your cases. This will increase pressures at a minimum, and possibly cause case rupture or separation, or a big KB!
The Hotchkiss-type MG's were designed around the case oiling, so pressure was not an issue with them. They however were not the best examples of MG's that came out of WWII. Oil on a cartridge in a combat situation cannot be a good thing, dirt and gunk getting on them, oil knocking out primers, etc. Chrome lined barrels were found to make functioning smoother when retaining the properties necessary for gas sealing ,and caused less heat damage caused on full auto weapons, and that's why they are commonly used on military weapons today.


Kids, don't try it at home! (or the range... )

 

[BluesBear]

I seem to recall that Remington Golden Bullet .22 ammo had a dry lubricant of some kind.

That is the lubricant on the bullet. That's why those Remingtons looked Yellow or Gold.
Winchester did the same thing with their Lubaloy coating. They were orange. The color was a die to signify that it had the new improved coating.
Winchester used the exact same coating on their .38 and .357 ammo except it was silver.
Federal High Velocity .22s in the 60s and 70s had an orangish coating as well. This coating was designed not to attract dirt like the older lubricants did. Since all .22 Short , Long & Long Rifle rimfire ammo has a heeled bullet the lubrication has to be outside of the case. Softer lube such as is used on modern inside lubricate bullets really attracts dirt.

Why if, this idea wouldn't work - why is Wolf coating their steel cases? And if they can coat steel, why can't that work with brass?

Uncoated steel will rust, whereas brass won't.
Where corrosion is a concearn they do coat the brass... with nickel.

Why not put the Teflon(R) on the inside of the chamber, instead? That way you won't have to pay for really expensive cartridges.

Anyone beside me remember the Universal Carbines of the late 1960s? The ones that were Teflon coated? They came in five colours, Black, White, Sky Blue, Olive Green and Gray.
The Teflon coating didn't last very long on the moving parts. In a chamber it's life would be very very short.

Why not include a dry lubricant in the propellant, something resistant to combustion (Teflon was mentioned) to be deposited as residue --this would make for a self-lubricating firearm, The lubricating residue would inevitably coat the chamber itself --albeit temporarily.

No it wouldn't.
In a self loading firearm the bullet, and it's attendant gases have already left the barrel before the slide starts to budge. Any lubricant which could stand that intense heat could possibly be deposited in the barrel like unburned powder but not in the chamber. Beside this is all moot in any other type of firearm as the casing remains in the chamber until manually extracted.

Case in point is that you can fire a 1911 without any recoil spring at all. I've done it. (I seem to recall that 1911 Tuner has done it as well.) The cases appeared normal since the pressure has already equalized in the barrel before the slide started to move.
In a recoil operated firearm, it is the mass of the slide, the friction of the case and simple physics that combine to keep the slide closed. In a hammer fired weapon such at the 1911 the mainspring has more effect on holding the slide closed after firing than the recoil spring. The recoil spring's main purpose is to return the slide to battery and recharge the chamber.

For those of you with access to full automatic weapons, fire off a full magazine. Then fire a magazine loaded with ammo that has been coated with some OneShot lube. You'll notice a definate increase in the cyclic rate.

Now look at HK weapons with their fluted chambers. Those flutes are designed to provide a slight extra grip to the casings to help retard unlocking.


The bottom line is that most modern small arms were designed around ammunition loaded with unlubricated brass cases.

entropy is correct, don't go altering the equation.

 

[JPL]

A friend of mine was looking over my shoulder when I was reading the initial message and said two words...

"Back thrust" and mumbled something about that being a problem when the gun is still locked.

What the heck is that?

He left before I could ask him about it.

 

[George Hill]

Looks like HORNADY liked this idea. Their TAP ammunition now sports brass that is coated in polished and blackened nickle.
That and it looks pretty danged cool too.
Even have it in pistol calibers.


Hornady, you are welcome. Now send me some boxes and we'll call it even.

 

[IZinterrogator]

Okay, so Teflon will wear, anyone with a non-stick pan will agree if they have owned one long enough. What about coating the chamber and barrel with a substance like NP3?

 

[George Hill]

Well, that was one of my earlier thoughts... Hornady decided on using nickel as the coating and it solves all the earlier objections over lubing the cases.
According to Hornady, it makes for smoother feeding. But they forgot to mention that it makes for easier-smoother extraction as well.

 

[Hardware]

IIRC there was a French LMG that required the crews to pre-lube their belted ammo due to frequent extraction failures that would rip off the base of the case. I believe one of the WW2 Japanese LMGs had the same problem and the same solution. So lubing cases doesn't always cause problems, sometimes it solves them.

Of course I've never had an extraction failure, so take this FWIW.

 

[Sean Smith]

Nickel plated brass is pretty common, has been for quite a while. Nickel gives you better lubricity than brass does.

Chrome plated chambers have been pretty common in military applications too, mainly to reduce malfunctions.

And if you want easier extraction, you can flute the chamber. Schuemann found a way to do it with their AET series of 1911 barrels that doesn't chew up the brass.

 

[dev_null]

Have you ever had a round stuck in the chamber? Not just a failure to extract - I'm talking STUCK. You have to get out a cleaning rod and bang the case out... and if that doesn't work and the base of the brass is ripped off, then a gunsmith has to use some tools to rip the brass out from the inside.

Dunno about my guns, but I'm off to wax all my lightbulb sockets. Extracting stuck bulb bases is loads of fun, especially if you forget to turn off the breaker.