Brass ageing ?????

[RW]

I had some 270 win loaded factory !50 round nose that I came by in the old rem green boxes and I would occasionally shot some for the brass now these were factory cartridges and they would not group for s**t but I was just going to use them to reload and one day I blew a primer and then split some necks and the person next to me asked what load I was using and I replied they were factory and he looked at them and said I should call Remington which I did and gave them the code on the flap turns out they were made just after WWII and they said do not shoot any more of them that the brass that old would be brittle!! Ron

 

[Webster]

I had some 270 win loaded factory !50 round nose that I came by in the old rem green boxes and I would occasionally shot some for the brass now these were factory cartridges and they would not group for s**t but I was just going to use them to reload and one day I blew a primer and then split some necks and the person next to me asked what load I was using and I replied they were factory and he looked at them and said I should call Remington which I did and gave them the code on the flap turns out they were made just after WWII and they said do not shoot any more of them that the brass that old would be brittle!! Ron

The brass doesn't become brittle from age. It has to be corrosion from chemicals.

 

[rwj]

How was the brass cleaned? SS pin tumbling usually removes carbon from the case neck that acts as a bullet lubricant.

 

[nicholst55]

It is called age harding and yes it does .
How much would depend on where it was stored . Larry

General Hatcher wrote about this many years ago, and called it 'age-cracking,' if memory serves. This was with WWI-vintage ammo between the wars. They began annealing the case neck and shoulders during manufacture, and that pretty much eliminated the problem for the military.

 

[LarryDScott]

Sample cases have been sent to Kevin Thomas, and to Alex @ AMP. One or both can determine what caused this. Thanks for everyones input. LDS

 

[Webster]

Can brass become brittle w/age????
When I attempted to pull the bullets w/an inertia hammer, they acted as if
they were glued in the case, but only had .003 NK tension. During the
pulling process, another case separated into 2 parts leaving the bullet in the neck,
while breaking my inertia hammer at the same time.

Not sure how to start this discussion. About two weeks ago I reloaded a few 6BR cases with new 8208 powder. About 5 days latter I decided to reduce the COAL. They made a popping sound as the bullets went deeper. I don't know if we will ever get a good answer to this sticking. I know enough about metallurgy to believe the brass isn't changing in any way. The only thing that makes sense is a small amount of corrosion or chemicals reacting with the surface of the brass. Smokeless powder always contains a very small amount of acid and other chemicals that cannot be removed from the nitrating of the cellulose.

Some people have mentioned that two perfectly polished and flat surfaces of metal will bond together. Not really true. Machinist steel Jo block standards are flat to several millionths of an inch. You cannot pull them apart but you can slide them apart. Years ago I soaked a case in household ammonia for about a week. You could crumble the case with you fingers. Tried to duplicate this without success. Where I used to work I could have analyzed a case I.D. for corrosion. I was not aware of the problem then.

https://en.wikipedia.org/wiki/Smokeless_powder

Below a section clipped from the article.

Instability and stabilization[edit]
Nitrocellulose deteriorates with time, yielding acidic byproducts. Those byproducts catalyze the further deterioration, increasing its rate. The released heat, in case of bulk storage of the powder, or too large blocks of solid propellant, can cause self-ignition of the material. Single-base nitrocellulose propellants are hygroscopic and most susceptible to degradation; double-base and triple-base propellants tend to deteriorate more slowly. To neutralize the decomposition products, which could otherwise cause corrosion of metals of the cartridges and gun barrels, calcium carbonate is added to some formulations.

To prevent buildup of the deterioration products, stabilizers are added. Diphenylamine is one of the most common stabilizers used. Nitrated analogs of diphenylamine formed in the process of stabilizing decomposing powder are sometimes used as stabilizers themselves.[2]:28[5]:310 The stabilizers are added in the amount of 0.5–2% of the total amount of the formulation; higher amounts tend to degrade its ballistic properties. The amount of the stabilizer is depleted with time. Propellants in storage should be periodically tested for the amount of stabilizer remaining, as its depletion may lead to auto-ignition of the propellant.

http://www.freepatentsonline.com/2292469.html

Lengthy article describes how difficult it is to remove residual acid and other chemicals after cellulose is reacted with sulphuric and nitric acid.

It’s easy to analyze the finished nitro cellulose for residual acid. There is a spec for the max permitted. Doesn’t mean they cannot go over the spec a little.

 

[JRS]

Not sure how to start this discussion. About two weeks ago I reloaded a few 6BR cases with new 8208 powder. About 5 days latter I decided to reduce the COAL. They made a popping sound as the bullets went deeper. I don't know if we will ever get a good answer to this sticking. I know enough about metallurgy to believe the brass isn't changing in any way. The only thing that makes sense is a small amount of corrosion or chemicals reacting with the surface of the brass. Smokeless powder always contains a very small amount of acid and other chemicals that cannot be removed from the nitrating of the cellulose.

Some people have mentioned that two perfectly polished and flat surfaces of metal will bond together. Not really true. Machinist steel Jo block standards are flat to several millionths of an inch. You cannot pull them apart but you can slide them apart. Years ago I soaked a case in household ammonia for about a week. You could crumble the case with you fingers. Tried to duplicate this without success. Where I used to work I could have analyzed a case I.D. for corrosion. I was not aware of the problem then.

https://en.wikipedia.org/wiki/Smokeless_powder

Below a section clipped from the article.

Instability and stabilization[edit]
Nitrocellulose deteriorates with time, yielding acidic byproducts. Those byproducts catalyze the further deterioration, increasing its rate. The released heat, in case of bulk storage of the powder, or too large blocks of solid propellant, can cause self-ignition of the material. Single-base nitrocellulose propellants are hygroscopic and most susceptible to degradation; double-base and triple-base propellants tend to deteriorate more slowly. To neutralize the decomposition products, which could otherwise cause corrosion of metals of the cartridges and gun barrels, calcium carbonate is added to some formulations.

To prevent buildup of the deterioration products, stabilizers are added. Diphenylamine is one of the most common stabilizers used. Nitrated analogs of diphenylamine formed in the process of stabilizing decomposing powder are sometimes used as stabilizers themselves.[2]:28[5]:310 The stabilizers are added in the amount of 0.5–2% of the total amount of the formulation; higher amounts tend to degrade its ballistic properties. The amount of the stabilizer is depleted with time. Propellants in storage should be periodically tested for the amount of stabilizer remaining, as its depletion may lead to auto-ignition of the propellant.

http://www.freepatentsonline.com/2292469.html

Lengthy article describes how difficult it is to remove residual acid and other chemicals after cellulose is reacted with sulphuric and nitric acid.

It’s easy to analyze the finished nitro cellulose for residual acid. There is a spec for the max permitted. Doesn’t mean they cannot go over the spec a little.

The very thing NORMA explained many years ago.

 

[SheepDog]

I can look up the process of age hardening in my metallurgy books but I recall there are two processes of age hardening in metals. One is precipitation and is common in copper and aluminum alloys. As I recall the metals react with internal chemistry through minute fluctuations of temperature and humidity.
Age hardening is a real and understood property of some metals.

 

[Webster]

I can look up the process of age hardening in my metallurgy books but I recall there are two processes of age hardening in metals. One is precipitation and is common in copper and aluminum alloys. As I recall the metals react with internal chemistry through minute fluctuations of temperature and humidity.
Age hardening is a real and understood property of some metals.

Cartridge brass does not age harden. It is a single phase alloy with no elements that would cause age hardening or precipitation. Some bronze alloys may age harden. Every alloy has it's own characteristics and properties.

 

[danny]

My experience with brass splitting:

Some years ago I purchased some new, pulldown USGI 7.62MM brass (a lot of 1000). I loaded it like any brass I had used in this rifle prior to using this brass.

Upon firing the brass, I got a lot of split necks. I then proceeded to attempt my first session of annealing, prior to buying an annealing machine. I used a propane torch, cordless screwdriver and Tempilaq. The results, as far as neck cracking is concerned was a success. I had no more split necks, BUT, after a while, I had a case split in the body. The results were actually one large lengthwise split with one or more spiderweb cracks. As you can't anneal the body, I called it quits with that brass and scrapped the whole lot. I have heard that brass can become brittle from the decomposition of powder, and that often (usually, always?), government entities surplus the ammuntion when it is determined to be of an age that the ammunition could be going bad, or is determined to be bad. I can not refute or support what I have heard, nor do I know that my brass, if it got brittle due to powder decomposition could be successfully annealed. These are just my real world experiences along the lines of the original posting, and should be taken at face value.

Danny

 

[Texas10]

Larry,

You mentioned "excessive growth" and I think this is key to your issue. What if, for the sake of argument, your annealer is over-doing it, and what you've got is a truly annealed neck/shoulder (soft brass) instead of a stress relieved neck/shoulder, which is what we are actually trying to do when "annealing". I see you mention possibly "over doing it" regarding your annealing process.

What you would possibly have is a rapid transition between too soft brass and work hardened and this is where the brass would tend to stretch and separate, and this combined with too much shoulder bump, again the result of too soft brass, might combine to create the separation issue.

Just a thought. I hope this helps.

 

[danny]

Larry,

You mentioned "excessive growth" and I think this is key to your issue. What if, for the sake of argument, your annealer is over-doing it, and what you've got is a truly annealed neck/shoulder (soft brass) instead of a stress relieved neck/shoulder, which is what we are actually trying to do when "annealing". I see you mention possibly "over doing it" regarding your annealing process.

What you would possibly have is a rapid transition between too soft brass and work hardened and this is where the brass would tend to stretch and separate, and this combined with too much shoulder bump, again the result of too soft brass, might combine to create the separation issue.

Just a thought. I hope this helps.

If that is so, he should be able to do the "pliers test" on the neck to see if over annealing has happened.

Danny

 

[Webster]

My experience with brass splitting:

Some years ago I purchased some new, pulldown USGI 7.62MM brass (a lot of 1000). I loaded it like any brass I had used in this rifle prior to using this brass.

Upon firing the brass, I got a lot of split necks. I then proceeded to attempt my first session of annealing, prior to buying an annealing machine. I used a propane torch, cordless screwdriver and Tempilaq. The results, as far as neck cracking is concerned was a success. I had no more split necks, BUT, after a while, I had a case split in the body. The results were actually one large lengthwise split with one or more spiderweb cracks. As you can't anneal the body, I called it quits with that brass and scrapped the whole lot. I have heard that brass can become brittle from the decomposition of powder, and that often (usually, always?), government entities surplus the ammuntion when it is determined to be of an age that the ammunition could be going bad, or is determined to be bad. I can not refute or support what I have heard, nor do I know that my brass, if it got brittle due to powder decomposition could be successfully annealed. These are just my real world experiences along the lines of the original posting, and should be taken at face value.

Danny

If you have stress corrosion cracking from chemicals annealing won't repair the microscopic cracks.

 

[Webster]

I had some 270 win loaded factory !50 round nose that I came by in the old rem green boxes and I would occasionally shot some for the brass now these were factory cartridges and they would not group for s**t but I was just going to use them to reload and one day I blew a primer and then split some necks and the person next to me asked what load I was using and I replied they were factory and he looked at them and said I should call Remington which I did and gave them the code on the flap turns out they were made just after WWII and they said do not shoot any more of them that the brass that old would be brittle!! Ron

You posed a question on our web site in regard to C260 cartridge brass age hardening with time.
The properties of copper based alloys (without plating) do not change based on "shelf life".
The surface condition may be impacted by storage conditions; material will tarnish over time.
If the stains become significant enough that could have a negative impact on formability.

Regards,
Joan Brennan
Technical Service & Market Development Engineering Manager
GBC Metals dba Olin Brass
East Alton, IL
Office 618 -258-5689 / Cell 618-301-7810
Joan.Brennan@olinbrass.com

 

[danny]

If you have stress corrosion cracking from chemicals annealing won't repair the microscopic cracks.

Thanks. I suspected that much, and as I said, I could only report my actions and observations. In my case, there must have been more than one thing going on simultaneously. I think that under the circumstances, scrapping it was a reasonable safest course of action.

Danny

 

[acthomas]

Couple of things -

I had a box of Norma 6.5 X 54 MS with steel-jacketed bullets (at least the jackets were ferromagnetic) that produced a galvanic cell with the case, which caused what looked like rust to develop and expand the neck enough to split. Total loss.

Working with an R2 Lovell, the cases that arrived with the rifle failed upon firing. Newer (slightly) cases worked OK. Had a similar experience with a Hornet with brass maybe half a century old.

had the problem with the ammo that I got , half of it cracked thank God for the new 25/20 stevens single shot brass that I make the r2 lovell out of

 

[BoydAllen]

These should keep you busy for a while.

https://www.govinfo.gov/content/pkg/GOVPUB-C13-5ad5093bab9313b64650a80f8143ec0a/pdf/GOVPUB-C13-5ad5093bab9313b64650a80f8143ec0a.pdf

Stress corrosion cracking of copper-base alloys

This thesis describes the stress corrosion cracking of a series of aluminium bronze alloys and attempts to characterize the cracking in relation to the various mechanisms proposed. The theories of cracking applicable to the aluminium bronze/ammonia system include; the anodic dissolution, the...

unsworks.unsw.edu.au

 

[Tommie]

had the problem with the ammo that I got , half of it cracked thank God for the new 25/20 stevens single shot brass that I make the r2 lovell out of

Just A Reminder: Zombie Threads

. It kind of helps weed out this type of behavior. Killjoy.

forum.accurateshooter.com

 

[wizarc]

It is called age harding and yes it does .
How much would depend on where it was stored .

 

[gambleone]

Thread is 4 yrs old.