Brass Hardening with Age?

[H.Callahan]

Today I ran across some loads that I did for my Model 29 back in 1974. They were meant for a hog hunting trip that I was going to take (to Texas, IIRC). At the last minute the trip fell through and the loads got put away for another time. They were stored in a sealed container with dissectant in my parents basement where all my reloading stuff was then located. We moved back into the house where my parents lived a couple of years ago.

At any rate, the loads were 22gr of 2400 under a 240gr JSWC. This was a load that I had worked up in my 29. It was stout, near the then recommended maximum, but performed well and didn't show any pressure signs in the gun. On the notes on the box, I had put them up with brand new WW brass. That jives with my memory as I usually put up loads meant for special hunting trips in new brass.

Looking at them today, they still looked pretty good, a little pantena on the outside of the brass, but all-in-all, looking pretty good. However, since they were approaching 40 years old and the load was over what is NOW the recommended max load, I decide that instead of following my first inclination to just shoot them, I decided to pull them apart with an inertia puller, salvage the bullets, brass and primers and restuff them with a less frenetic load.

I started pulling them down, got about 10 rounds into it and noticed a number of them broke down really easily. I looked at the brass on those and they all had cracks either at the mouth or in the middle of the brass approximately where the base of the bullet was. I then checked all 10. Those that pulled easily were all cracked and the tough to pull ones LOOKED ok. I then check all of the remaining loaded rounds and they all looked ok. Absolutely no visible cracking anywhere. I pulled all the rounds (there were 100 total) and 55 exhibited cracks in the case after pulling. I also checked the insides of the cases and they were, indeed, bright and shiny indicating then new brass (back then, I hand washed brass and even once fired were dark on the inside).

The only thing I can come up with is that the brass somehow age hardened enough to crack the cases when the bullets were pulled. I've not heard of that, before, as in the past, I have shot countless rounds that were pretty old without any undue problems. The only reason that I didn't shoot these is because I was a little concerned because it was a pretty heavy load that, although was in-bounds back then, would be considered overpressure now.

I am also concerned about the 45 cases that APPEAR to be ok. Can I trust these? I don't intend to load them heavy as I am punching more paper than animals these days, but I still have it in the back of my mind there might be a problem with these supposedly still good brass.

[Dan Cash]

Personally, I would shoot the stuff but that is me. As for the cracking, it sounds like the brass has reacted with some amonia based chemical. You might investigate what vapors are given off by the dessicant you used during storage. Since this was new brass, I don't guess you tumbled them in any media containing Brasso. Were the cartridges in contact with cardboard while in storage? I have some 1915 vintage Remington 7mm amo that has the odd cracked case which I attribute to the acids in the cartridge boxes.

[Cap'n Morgan]

This is from Norma's homepage:

"The case neck is annealed to become softer. This prevents gas leaks and enables the case to hold the bullet firmly for at least 10 years without cracking as a result of aging material."


I'm not sure the cracking is actually caused just by aging, but more likely stems from a phenomena called stress-corrosion cracking. If aging alone was the problem, the scrapyards would be filled with cracked brass instruments [smilie=1:

[TheBigBang]

Something more than aging going on there. I've shot old cartridges with no problems & I've pulled bullets from rounds older than that, with no cracking. I have "collector" cartridges over 100 yr.s old & they certainly weren't stored in airtight containers & while I haven't shot them, they exhibit no signs of cracking or other "weakness".

[fatelk]

I'm curious too. I have some '06 that I reloaded 20+ years ago, and a lot of it had neck splits when fired. It wasn't new brass but it was good once fired.

On the other hand I've shot plenty of WWII and Korean war era surplus and rarely had cracks.

[H.Callahan]

The cartridges were in a styrofoam tray inside a cardboard ammo box then sealed in a burped Rubbermaid container with two packets of desiccant (probably recovered from something back then -- probably some reloading stuff shipping boxes). Container unburped when opened.

I am totally perplexed and still a little gunshy of the remaining brass.

[H.Callahan]

BTW, with all the forums here, why isn't there one for brass?

[MtGun44]

2nd on the ammonia-bearing compound. The neck is under high tension and there is a
phenomenon called stress corrosion cracking. Under certain conditions of relatively
high stress (case neck probably qualifies) certain alloys (brasses and some SS alloys) can
exhibit a intergranualar corrosion that will be seen as a sudden crack. No visible corrosion
is usually seen, just the crack.

Is it possible that mouse urine has been near them. This is common if a mouse nest winds
up in the same box or drawer. Some cleaning compounds contain ammonia, too.

I used to have a batch of 1943 headstamp Belgian 7x57 milsurp ammo. Every single case neck
was pre-cracked. I always thought that this may have been wartime sabotage if the ammo was
made for Germany under duress while Belgium was occupied. Workers could apply ammonia
compounds to the packaging material and eventually the brass would crack.


Bill

[H.Callahan]

While I can't rule it out 100%, there was no indication of anything like mice our any other intrusion into the container. It was still airtight when I opened it.

...and as was speculated, no polish on any of them as the brass was brand new.

[.22-10-45]

Hello, H. Callahan. That brass has been under tension for 40 years..the expander ball was probably at least .003" under bullet die., plus there is probably a pretty firm crimp. Brass will crack under stress..I have had it happen on loaded cases less than 10 years old..and no..there were no chemical fumes or rodent urine present.

[TheBigBang]

Mice are incontinent or at least, they urinate everywhere they go, if one had just crawled over the container, styrofoam tray or desiccant packs before the container was sealed, you could have gotten mouse urine contamination, albeit a small amount. Styrofoam is actually mostly air anyway, so if there was ammonia vapor in the air where the styrofoam was or had been, it might have absorbed some of that vapor. If the desiccant packs were used, they might not have even been able to absorb anymore vapor from the air, it MIGHT even be possible that they released something harmful that they had absorbed earlier, but I don't know.

Unlike .22-10-45, I have not had loaded cases under 10 yr.s old crack on me. Brass will certainly crack under enough stress, it will crack from repeated "working" or from being "over-worked" (i.e. stretched too much). I think however, most of us have fired or at least seen ammunition that was more than 40 yr.s old & many have reloaded cases that old or even MUCH older. So, I still say there is something more here than just "aging" or the "normal" stresses of loading. It's also quite possible you got a bad batch of brass, there may have been some defect in the manufacturing or it may have been exposed to something like ammonia somewhere between the time it was made & the time you got it.

[H.Callahan]

Ok, but why was the brass fine prior to any attempt to pull the bullets? After the first 10, I checked every remaining piece and they appeared fine. The cracks appeared after the bullets were pulled.

Bigbang, that is certainly possible, I guess... Just kinda unnerving not being sure of the cause. I just never encountered any thing like this before, particularly with "new brass".

[303Guy]

From what I remember some brasses will age crack more readily than others depending on the make-up but is known to age harden and go brittle. If those un-cracked cases get annealed they will likely last as long as new cases.

[TheBigBang]

Well, while the exact WHY is something I'm sure we'd both love to know, unless you have some rather sophisticated testing equipment, we may never know the real answer. Like you, anytime I encounter a situation like this, I have a burning desire to know "WHY" & I hate it when I don't get the answer. As for at least a POSSIBLE "why" the bass did not crack until the bullet was pulled, even if the brass was brittle or had become brittle, it probably hadn't really been subjected to ANY real stress just sitting there since '74. When you stuffed them into that inertia puller & "whacked" the bullets out, you subjected it to much more stress than what was probably just some light "handling" when you first found them. I'm not saying that it was necessarily the stress in & of itself that did it, but that it was maybe stress on brass that had something wrong with it. Take, for example, an old wooden stair case with hidden termite damage, it may LOOK fine, if you just sit a flower pot or briefcase on the steps, it may not exhibit any sign of weakness, but if you put your body-weight on it, you end up in the basement & not because of the age of the staircase, but because it's been damaged by the termites.

[Von Dingo]

Just speculating.

Having heard of the early Federal .32 H&R Mag brass that was prone to splitting. There are a lot exacting procedures that form the mixture of brass we use for cartridges. Could just be brass that is off a little at the molecular level.

The part of the sheet that this brass came from may have been from the top of the crucible when it was mixed, last pour on Friday.

[Jeff H]

Ok, but why was the brass fine prior to any attempt to pull the bullets? .........

I recently had a box of handloaded .257s from about 20 years ago start cracking at the necks just sitting in the cardboard box. There was green crud growing around the cracks and the bases of the bullets were green and fuzzy. Storage was in a wooden cabinet in the hous and subject to no unusual or especially advers conditions. In this case, it was new Remington brass back when it was loaded. When I crushed the necks to scrap them, the brass was brittle and broke.

Probably twenty or more years ago, I had this happen but there were no cracks until I fired them. Accuracy was horrible and I started looking things over. That's when I noticed the cracks in what otherwise appeared to be very healthy cases.

For the real weird one, my Dad called me over one day to show me some brass he'd put up in zip lock bags just a couple years ago and some had green, fuzzy barnacles growing on it and some was just fine. Some was new and some was cleaned and processed before putting up.

No amonia in any of these instances - we learned about that one long ago and know to be careful about it.

As posted above, we both have cases that are VERY old which look just fine and I have loaded many cases that were easily over twenty years old. I have one .357 mag case left from a box of fifty I bought in the early eighties that still shows up when processing brass and it still gets loaded in some light loads for which I use mixed brass. No idea how many times that one case has been loaded.

[TheBigBang]

Jeff H, maybe there wasn't any ammonia around, but that "green crud" you mention seems to indicate there was SOMETHING they had been exposed to causing corrosion.

[Jeff H]

Jeff H, maybe there wasn't any ammonia around, but that "green crud" you mention seems to indicate there was SOMETHING they had been exposed to causing corrosion.

Whatever it is - I can't put my finger on it.

The growth was mostly on the inside of the case and started to creep out of the cracks. A few that hadn't cracked had green stuff on the bases of the bullets as well.

They were very brittle too. When I squeazed the necks to decommission them, they broke at the shoulder too. I pulled the bullets with my fingers - no effort.

The ones that split upon firing years ago showed no signs of corrosion, just split necks - or cracked necks I should say. It wasn't like a normal split that develops - it cracked all the way to the mouth,

[Multigunner]

Stress Corosion cracking of cartridge cases was first noticed when opened ammunition crates were stored in work rooms of calvary stables.
The ammonia fumes from horse manure were enough to set the process in motion.
Keeping ammo out of the stable areas was enough to prevent the problem from re-acurring.
Later The British in India during the 1920's found that enough ammonia was released into the air by flooding of fields during the monsoon that the SCC process was greatly acelerated. There was no way to prevent air from getting to cartridges once the seal on ammunition cases was broken.

The Brits then added an annealing step to case manufacture, made doubly difficult because the cordite filled .303 had the case necked formed after the charge was in place, and the stress of forming the shoulder is what caused the microscopic surface fractures that gives SCC its foothold on the brass.
WW1 era Remington .303 milspec cases were especially prone to SCC of the shoulder.

Mercury embrittlement is another possibillity for old brass, if a mercuric primer was used in conjunction with smokeless powder at some point in the case's history.

Mercury embrittlement was not an issue during black powder cartridge days, the thick soot of BP protected the inside of the cartridge case. When smokeless powder was used there was not enough fouling inside the cartridge case to form a protective shield.

[fredj338]

This is from Norma's homepage:

"The case neck is annealed to become softer. This prevents gas leaks and enables the case to hold the bullet firmly for at least 10 years without cracking as a result of aging material."


I'm not sure the cracking is actually caused just by aging, but more likely stems from a phenomena called stress-corrosion cracking. If aging alone was the problem, the scrapyards would be filled with cracked brass instruments [smilie=1:

Agree, I only see this with loaded ammo. I have some old magnum rounds, 20yrs or so, that almost all split on firing. The same aged, unloaded brass, reloaded & shot fine. So I am not big on storing lots of reloaded ammo. I am sure any ammonia bases cleaning solvents wouldn't help.

[popper]

Had the same problem with bought, LGS, 30-30 (1x fired?) 2 yrs ago. Looked fine , loaded, shot and most all the necks had small cracks, some split. Had the green grunge around the cracks. I don't buy fired brass anymore.

[243winxb]

back then, I hand washed brass Ammonia will cause stress corrosion cracking. Vinegar will cause dezincification. Brass becomes brittle after many year of storage. http://www.photobucket.com/joe1944usa

[H.Callahan]

Ammonia will cause stress corrosion cracking. Vinegar will cause dezincification. Brass becomes brittle after many year of storage. http://www.photobucket.com/joe1944usa
First, off this was brand new brass. I didn't wash it. Back then, I did not use vinegar or ammonia or anything containing ammonia. My washing of brass consisted of putting it in a bucket, filling it with water, swishing it around and dumping it all out. I wiped the outside with a clean shop towel and let the insides air dry The purpose was not to shine the brass in any way, but just to get the gunk off of it so sizing would not screw up the dies. Lubing consisted of RCBS lube on a pad. We didn't have all the alternative methods for cleaning and lubing like we have today.

BTW, additional information. I had several hundred 38 special WCs (my usual 3.0 gr of Bullseye under a 148gr HBWC -- my go-to target round) next to these 44mag rounds. They would have been loaded about the same time. Same general storage conditions, different but identical Rubbernaid container and the same kind of dessicant. The brass on these was not new and had been fired many times with the wadcutter loads. Checked all those rounds, pulled several and absolutely no problems with the brass. I'll probably shoot the rest.

[CGT80]

I had cracks in some 44 mag brass after I shot the rounds. They belonged to my grandfather and were loaded up at least 15 years ago. He let me borrow his 44 ruger single action to play with and and also gave me the box of ammo to use. I pulled some of the rounds apart and found that he loaded to the max load with red dot powder. Some cracked and some didn't. Factory, new, ammo did not crack and my reloads with a light charge of win 231 did not crack. I figured a combination of old stressed brass (from sitting around so long) and a load that was very hot with a fast powder just did the brass in.

[paul h]

How well brass survives storage depends on the composition of the brass, and how well it was stored.

I shot WWII era 45 acp ammo in the early 80's, and asside from one or two very mild loads, I don't recall any of the brass being cracked before or after it was fired. And that ammo was not carefully stored.

Then again I was given about 50 rounds of somebodies 6.5X55 handloads, and as I don't use anybody elses handloads, I broke them down. Some rounds had visibly green crud on the necks, others looked fine but had some corrosion when I pulled the bullets. I had near 100% necks cracked when I fl sized the brass.

[303Guy]

I had the idea that brass age hardens and that a loaded cartridge will split its neck eventuall. I also have the idea that if the neck in question can be anealed befor it actually crack, the case will continue to give good service. Anyway, I found this comment on the 'net;


brass and copper will withstand use better in an annealed state and as it returns to a hard condition it will crack, I have seen evidence of pipes that subject to vibration that have cracked. It is a part of service to remove copper or brass pipes on working machines and anneal them.

That could be hardening from mechanical cyclic stress. Thermal stress might do the same thing (cyclic warming and cooling).

The 'net is a wonderful place, full of speculation and opinions. Very hard to find real facts. Engineers and scientists are too busy to put information out on the 'net.

[40Super]

When I started reloading in the early '90's I cleaned all my brass in treated corn cob media , so none of my brass was subjected to any cleaners. I used(and still do use it sometimes), the RCBS case lube. Last year I broke down most of my old "rejects" or questionables ect.. Quite a few of them had some of that green corrosion/discoloration. I figured it was from the lube, I usually didn't wipe it of the inside real good so there was some in many of the cases. I'm sure it isn't "supposed" to be harmfull, but after 15years????

[MtGun44]

You got some of your info from a mechanical engineer with 40 yrs experience.

Bill

[303Guy]

Found something else;


I talked with Sierra a few times and seems that I did myself in having to store it in non conditioned air space. And that the contraction expansion rate between copper and brass IE bullet and case, is different enough that hot and cold will cause it to work harden itself.

I'm thinking stress corrosion is not the only culprit. I was given some 25-303 loaded ammo which was made from reforming primed military brass. Most of them were cracked or cracking, some right up the shoulder. These were not annealed befor or after reforming the necks and none had any sign of chemical action. It makes me think it was cyclic thermal stress that work hardened the brass to breaking point.

[.22-10-45]

Hello, everyone. Just a thought, I seem to remember Phill Sharpe in his Complete Guide To Handloading, mentioning alot of problems with surplus WW1 .30-06 brass cracking..he blaimed it on war time cost measures..they were scrimping on costly copper in the mills & had an excessive amount of zink.

[snuffy]

H.Callahan, How did the powder look? Since 2400 is double based, is there something that could be released if the powder was breaking down?

Seems I've heard of powder stabilizers running out of effectiveness, allowing nitric acid to escape the powder. It's the smell you sense when powder has aged, that sharp acidic smell.

A guy with the handle slamfire has researched powder breakdown extensively. He posts on TFL anf THR. Mostly he debunks the idea that powder lasts indefinitely.

From a post of his on TFL;


The lifetime of ammunition is primarily determined by the lifetime of the gunpowder inside.

A rule of thumb is 20 years for double based and 45 years for single based.

Temperature is the worst enemy of gunpowder.

Heat accelerates the deterioration/decomposition of powder and the rate is directly proportional to the Arrhenius equation. If you read in the Insensitive munitions literature, you will see that they use high temperature to accelerate aging of smokeless propellants.

ROLE OF DIPHENYLAMINE AS A STABILIZER IN PROPELLANTS;
ANALYTICAL CHEMISTRY OF DIPHENYLAMINE IN PROPELLANTS

Quote:
Nitrocellulose-base propellants are essentially unstable materials
that decompose on aging with the evolution of oxides of nitrogen. The
decomposition is autocatalytic and can lead to failure of the ammunition or disastrous explosions.
http://www.dtic.mil/dtic/tr/fulltext/u2/783499.pdf

Heat, as you can see in the report, will age gunpowder



Keeping moisture away from gunpowder is good as water is a polar molecule and interacts with the double bonds on the nitrocellulose molecule.


On this thread there;

http://thefiringline.com/forums/showthread.php?p=5106788#post5106788

Just another guess. A basement is usually cool-ER than if stored up in the house.

[bearcove]

I had some 20 yr old 44 mag jacketed bullet reloads. No animals around them, not even mice. Shot a dozen they all split half way down side. Shot a box of 40 year old 38 wad cutter factory ammo, no problem.

[Von Dingo]

One thing that hasn't been mentioned on any level, chemicals that our skin produces. Different folks have more acidic sweat and oils, once again, thinking out loud.

Many variables

[H.Callahan]

H.Callahan, How did the powder look? Since 2400 is double based, is there something that could be released if the powder was breaking down?
The powder looked great and smelled just like the 2400 I bought a couple of weeks ago. I didn't see or smell anything that would indicate any deterioration going on with the powder. I've been tempted to load a bit of it up (definitely not at a max load) and see how it worked.

That basement is pretty cool most of the time. My room was down there (the only finished part of the basement) when I lived in the house. It was pretty comfortable down there even before Dad installed central A/C.

[fatelk]

I would be inclined to wonder if it wasn't just a bad batch of new brass.



The lifetime of ammunition is primarily determined by the lifetime of the gunpowder inside.

A rule of thumb is 20 years for double based and 45 years for single based.
I've heard this before and have to wonder about it. I've shot plenty of pistol ammunition that is far older than 20 years. The oldest .45 acp round I shot was an original from 1914, and it worked fine. I've also used quite a bit of old powder in original cans, much more than 20 years old, that worked fine.

I have thrown some out when it's obviously been stored poorly and clearly gone bad, but I really have to question the 20 years for double based thing. My experience has been that, properly stored, 20 years is nothing.

[303Guy]

I would be inclined to wonder if it wasn't just a bad batch of new brass.I would tend to agree (bearing in mind there does seem to be more than one cause of cracking). The only cracked necks I've seen were on military brass and then not all of it. The worst ones were those necked down ones I mentioned which would therefore have suffered considerable work hardening considering they were likely already hard with age - and that would likely have been due to thermal stress.

[eck0313]

I doubt that there are any real hard and fast "rules" on stress cracks WRT ammo/brass storage. I've been shooting 30-06 brass that dates back to the 50's and recently shot WWII .45 ammo with no problems. I have had necks crack in the 30-06 brass, but that was after shooting them a great deal.

Military ammo/brass is made for long term storage.

At the other end of the spectrum, I've had nickle plated .45 ACP brass crack that is less than 5 years old, with only a few firings.

I recently shot some 44 Spl ammo that I loaded (Winchester brass with 250 gr cast Keith bullets) back in 1985 with no problems . . .

[bearcove]

The 44 brass that cracked for me was rumored to be defective (federal) but who knows?