Weird case failure.

[Pumpkinheaver]

I recently had a strange case failure that I haven't seen in my 20 plus years of loading my own. The entire joint of the case wall and head cracked and the extractor groove was shoved into the case. The round fired and functioned fine and I didn't even notice there was a problem until I was resizing brass and one wouldn't fit into my shell holder. Like I said I have never seen this before and was wondering if anyone else has.

Sorry for the crappy iPhone pictures
http://i176.photobucket.com/albums/w170/pumpkinheaver/Hunting/088762E1-DF79-4A6A-9EA0-B651D8FDA420_zpsynlakxon.jpg (http://s176.photobucket.com/user/pumpkinheaver/media/Hunting/088762E1-DF79-4A6A-9EA0-B651D8FDA420_zpsynlakxon.jpg.html)
Here you can see that the entire circumference fractured.
http://i176.photobucket.com/albums/w170/pumpkinheaver/Hunting/91E77CDA-816C-47D1-8BFB-A2DA86E5C0C3_zpsrquhgdkz.jpg (http://s176.photobucket.com/user/pumpkinheaver/media/Hunting/91E77CDA-816C-47D1-8BFB-A2DA86E5C0C3_zpsrquhgdkz.jpg.html)

Here you can see how much the extractor groove and case shortened when the case head was shoved into the case.

[S. Galbraith]

Never see that kind of failure before. Is that 10mm? How many times had the brass been reloaded?

[Pumpkinheaver]

I guess I should include cartridge and load data.

10mm auto plinking loads loaded with 5.5grs of Titegroup and my 180 TC powdercoated bullets.

[S. Galbraith]

I guess I should include cartridge and load data.

10mm auto plinking loads loaded with 5.5grs of Titegroup and my 180 TC powdercoated bullets.

Sounds reasonable. Not all brass is created equal though. Different combination of alloys, different qualities of heat treatment, and different dimensional specs. What was the brand of brass?

[Pumpkinheaver]

Never see that kind of failure before. Is that 10mm? How many times had the brass been reloaded?
The brass has been loaded a few times but only with light loads. This makes me doubt the integrity of all of the old Winchester brass I have. I think I'm gonna chuck it all into the scrap bucket.

[S. Galbraith]

The brass has been loaded a few times but only with light loads. This makes me doubt the integrity of all of the old Winchester brass I have. I think I'm gonna chuck it all into the scrap bucket.

Was it originally from Winchester white box target ammo? Usually this brass isn't as good of quality as the reloading brass that they sell.

[Pumpkinheaver]

The brass is from Winchester silver tip loads. They are old probably 20+ years but I have only recently gotten back into the 10mm.

[S. Galbraith]

The brass is from Winchester silver tip loads. They are old probably 20+ years but I have only recently gotten back into the 10mm.

Age shouldn't be a problem unless they were exposed to extreme temperatures, or left in conditions which could have caused mild corrosion. Other than poor quality of the brass, another possibility is that the original factory loading generated enough pressure to stress out the case head. Fired from a longer barrel?.....fired from a firearm with less chamber support?.....etc

[jsizemore]

How do you clean your brass?

[vzerone]

Age is a problem. Brass age hardens. Haven't any of you see old military ammo where the necks split just setting in storage?

For light loads there appears to be a lot of head expansion. I'm not talking about the case where rim pushed the extractor groove into the case. Speaking of that appears that would have taken some pressure to do. Recently SPEERS ballistic lab has be re-evaluating revolver/pistol cartridge pressure and found the 10mm was dangerously high and more then what it should be.

[SWANEEDB]

I guess I should include cartridge and load data.

10mm auto plinking loads loaded with 5.5grs of Titegroup and my 180 TC powdercoated bullets.

What brand of gun were you using?

[MarkP]

It looks like a cold shut; that occurs during the heading process. Similar to a forge lap, the material does not flow but rather folds over. If you section the case it will be more revealing.

[MarkP]

155980 The magenta line depicts what a cold shut looks like. The view is a sectioned 40 S&W case.

[longbow]

If they have been sitting a long time and exposed to anything corrosive it could be stress corrosion cracking.

First time I saw it demonstrated was at technical school where the instructor took a piece of drawn brass and put it into an ammonia solution then within a minute of so it had split longitudinally in multiple lines and flared open like a banana peel. No actual corrosion visible anywhere, just attack at stress lines.

I could go with the cold shut idea too.

It would be interesting to see a sectioned cartridge though if the split is all around it may be difficult to tell what caused it unless there is an obvious fold.

Strange nonetheless.

Longbow

[fryboy]

So ...you reinvented the 10 weak and mild ... :P
I do find it odd as well because I've never seen it before either