223 split necks from older ammo?

[pmd]

223 Split necks.
Has anyone experienced 223 split necks from older ammo.
I have about 300pcs of loaded 223 ammo - that I was just chronying and discovered almost all the necks are now split.
Ammo was loaded using purchased "processed and primmed" Lake City 223 brass. Bullet was/is 69gr HPBT.
I used this brass for years when I shot High Power rifle back in the day and never had an issue.
This ammo has been stored in an ammo can for about 20years. It did spend 3.5 years in a not climate controlled garage.
I plan on pulling the ammo apart.
Just curious if anyone else has had similar issues.
Thanks.

 

[markm87]

I've seen this once. My buddy had some of my loads which were stored inside, but they ran a swamp cooler a lot. There were some green oxidation found on some of the cases. I wanted to blame the moisture of the swampy, but never could confirm.

Depending on the "processed" that the brass went through, it could be an aggressive neck down and expander ball that hardened the necks.

 

[CJ6]

Not 223, but I had an issue with 280 Rem brass. It was 42 year old NEW OLD STOCK that split when fired for the first time. I annealed some after the first splits and still had some that split, so I trashed them.

 

[Pawnee Bill]

The brass has probably never seen an annealer. The military had that problem years ago. That's why you see that pretty anneal color on all GI ammo now.

 

[Webster]

View attachment 1580836223 Split necks.
Has anyone experienced 223 split necks from older ammo.
I have about 300pcs of loaded 223 ammo - that I was just chronying and discovered almost all the necks are now split.
Ammo was loaded using purchased "processed and primmed" Lake City 223 brass. Bullet was/is 69gr HPBT.
I used this brass for years when I shot High Power rifle back in the day and never had an issue.
This ammo has been stored in an ammo can for about 20years. It did spend 3.5 years in a not climate controlled garage.
I plan on pulling the ammo apart.
Just curious if anyone else has had similar issues.
Thanks.

I would think the brass was resized, loaded and fired many times without annealing. 1 or 2 reloads shouldn't work harden the neck enough to cause failure? In any case you have to junk them.

For stress corrosion to occur you need humidity or dampness and exposure to chlorine containing chemicals. Chlorine is the big problem. Probably a few other chemicals. From my experience examining cross sections on a microscope, stress corrosion most commonly branches out in several directions.

 

[Krogen]

Not with .223 Rem but with .222 Rem. I shot some handloads that had been sitting for 15 years or so. I had reloaded them a dozen or so times without issue. Took a lot of varmints with them. Then they sat after my varmint hunting buddies decided their armchairs were more interesting. What fun is it by yourself? Anyway I decided to shoot these cartridges at the club a while back. Every neck split, but not lengthwise. They split circumferentially. It was like losing old friends.

 

[pmd]

Pulled all the bullets - the split necks made that task easy...

 

[K22]

No, I have never seen this type of "crack' in reloads. The "cracks" I have seen are the fatigue failures in the case neck that often occur in cases loaded, sized and fired many times. Those type of fatigue failures are not hairline cracks like those pictured. They begin as faint areas in the neck and open up usually when the case is fired.

However, I never had rifle reloads sitting around more than a year and half.

Those hairline cracks pictured look like stress cracks related to time that I have seen in industry based on my years in non-destructive testing. This is just a guess but what might be happening is that the case neck is shrinking over time and being restrained by the bullet, the stresses are being created and as time increases with the stress cracks propagating. If there is a metallurgist reviewing this post maybe that person can chime in and offer their professional opinion.

Yet I have seen very old military ammunition without time related stress cracks.

 

[Coyotefurharvester]

I had some 15 year+ old 17 Rem reloads crack necks during firing. The brass had been fired, loaded a couple times with standard RCBS die set, no annealing. I saw the cracked necks( did not crack all the way to case mouth) after a couple shots. A hammer style bullet puller would not work, until I seated the bullets 0.005 deeper. Seating deeper each made an audible crack. A couple necks cracked during the bullet pulling, brass that didn't was annealed and loaded a few with same load, all shot without cracking. In the end it wasn't a lot of brass, so it went in the recycle bin, as I have plenty of new 17 rem brass and didn't want to put my Lilja barrel at risk.

 

[RegionRat]

There can be many reasons for the cracks. Sometimes it is the quality of the brass up front, sometimes it is what we have done, and sometimes it is outside attack by chemicals we have either left behind in our processing or in a bad storage environment.

Without the labs, I wouldn't be able to tell you what happened here, but this is not rare. Lately, I have has splits like those on 17HMR from CCI, and also Fiocchi varmint ammo in more than one caliber, and this is new factory ammo. Even after culling the unfired splits, more show up after firing that must be culled again when I process them, and that is with annealing before sizing.

I used to run laboratories and when I looked at these Fiocchi necks, I determined the failure was an initial brass quality problem. Dirty alloy combined with poor heat treat during processing, but not SCC.

Here is another link to describe season cracking which is a form of SCC or stress corrosion cracking, just to show you how long the battel has been running with split necks....

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

 

[pmd]

....

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

Thanks for the info and link..

 

[243winxb]

Seen it many times in 5.56/223 brass. Over working the necks with standard die #1.

Brass fired when new. Reloaded and stored since 1997. Nothing new, happened before with brass washed in a vinegar solution. But this brass was not washed, just wiped and loaded.The cause seems to be over working of the case neck when FL sizing. Loaded in 1997 IMR4198-20.5grs Win 55 gr fmjbt .

Had 100 factory fired ammo PMC 223 , the reloaded brass all cracked, except 3 didnt, ON 1st reloading. Annealing issue, my guess?

5.56/223 seems to come with a donut.

Use FL bushing dies or neck turn the brass, seem to provide longer life. No always.

Never store ammo for years, a rule i now follow. The Ammonic carbonate from burning powder, will attack the brass, in storage. Making it brittle.

 

[243winxb]

Some Hormady 6.5 Creedmore brass, of poor quality, split.

From my post here

 

[searcher]

Given that the brass was "once fired", and assuming that to be correct, I'll say it is not the lot of brass that is the problem- as it wouldn't likely be all one lot. When brass is recycled - it can be done many different ways with many steps that might not be done when just reloading our own fired cases. Notably, a lot of mil brass gets stepped on and such when in the field/range. To completely iron out the dings and dents - an oversized sizing ball was probably used before sizing. That can impart much more work hardening than a regular resizing. If the brass had been annealed prior - or even after neck opening, it would not have likely occurred - but the processors don't usually anneal. I've had brass start splitting necks after three or four firings without annealing- but not all of them as in your case. I'd guess there was just a lot of work hardening done to the brass in the methods the processor used. Multiple lots of mil brass just don't all do that without some hardening.

 

[243winxb]

using purchased "processed and primmed" Lake City 223 brass.

Possibly sold as scrap. The military testing has a chemical dip that ages brass fast, like it was in storage. After firing, its was sold as scrap.

The military tests will fire Full auto 5.56 gun till the gun fails. Chambers may become large. Barrels will fail. Again, the brass was sold as scrap.

Processed brass can include roll sized brass. This may weaken the case head, if brass fired in worn chambers.

LC brass is not annealed as much as some match brass. LC is made to be fired 1 time, not reloaded. The Nato LC i have shot in my M16A1 is a lot hotter then any maximum loading from Hodgdon.

LC of mixed headstamp, if given the full Benchrest brass treatment, can produce good groups with Sierra's 69 gr match bullets.
Sorting by weight.Savage factory barrel. Light weight Axis.

 

[pmd]

Thanks for all the information.

 

[Webster]

There can be many reasons for the cracks. Sometimes it is the quality of the brass up front, sometimes it is what we have done, and sometimes it is outside attack by chemicals we have either left behind in our processing or in a bad storage environment.

Without the labs, I wouldn't be able to tell you what happened here, but this is not rare. Lately, I have has splits like those on 17HMR from CCI, and also Fiocchi varmint ammo in more than one caliber, and this is new factory ammo. Even after culling the unfired splits, more show up after firing that must be culled again when I process them, and that is with annealing before sizing.

I used to run laboratories and when I looked at these Fiocchi necks, I determined the failure was an initial brass quality problem. Dirty alloy combined with poor heat treat during processing, but not SCC.

Here is another link to describe season cracking which is a form of SCC or stress corrosion cracking, just to show you how long the battel has been running with split necks....

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

I used to do metallurgical failure analysis. Could you explain what you thought made the brass poor quality. Did it contain junk like metal oxides. Most molten metals at some time in melting and processing are carried in cast iron vessels. They can pick up oxides from the pots and molds. The oxides are stress risers. I'm, lucky I never had a real neck splitting problem. I may have lost 5-10 cases in 50 years. It's been 11 years since I retired. I cross sectioned about 20 cases and gave them a metallographic polish and examined them on an optical microscope. They always contained very small black particles. Never did EDS on them. Without reviewing I think AMPS website shows black specks of particles in their etched metallographic pix.

 

[243winxb]

Could you explain what you thought made the brass poor quality.

Annealing is one. Years ago, some 5.56 Nato had case head separations in a Galil , but not our M16s.

Seems Winchester was skipping 1 annealing to speed up the process, when they were running LC.
The extra interdraw anneal, stress relieves the case head area at around 480F degrees.


https://discover.dtic.mil/ page 35 starts "Metallurgical Investigation" @ link below.

Link page #9 & 10.
The principal cause of case rupture was traced to elongated
grains.

All brass is 70/30 or close to it. Copper/zinc. As i am sure you know.

 

[JerkyFreak]

Happened with quite a few of the old target rifle shooters that used to keep their ammonia-based barrel cleaners like Sweets 7.62 in the same box or cabinet as their brass.

Apparently ammonia fume also cause brass to crack like that under strain.

 

[Webster]

Happened with quite a few of the old target rifle shooters that used to keep their ammonia-based barrel cleaners like Sweets 7.62 in the same box or cabinet as their brass.

Apparently ammonia fume also cause brass to crack like that under strain.

Years ago I soaked a case in house hold ammonia for a week or 2. I could crumble the case in my fingers. I tryed to repeat it several years later. Couldnt crush the case in my fingers???