Cracked shoulder

[DocCarbon]

I do but I don’t have any idea of what you are thinking so until I do, I’m not one for mystery testing. Care to elaborate??

I'll assume You have it figured out then .

 

[markT]

It's a "Liberty Crack"...
That's is really something different for sure.

 

[Tommie]

About a year ago I slipped on ice and had a cracked shoulder

 

[DocCarbon]

Original Case Material: 70% Copper, 30% Zinc (260 Alloy)
• Susceptible to Stress Corrosion Cracking (season cracking)
– Originally Observed by British in India on Brass Cartridge Cases Stored in
Stables & Exposed to Horse Urine
– Caused by combination of material, residual stress & corrosive atmosphere
– Residual stress caused by forming processes
– Corrosive atmosphere from nitrogen bearing compounds in propellant
– Aggravated by “dezincification” of brass during processing
– Causes internal case wall split that propagates to exterior during firing
– Gas Wash on Exterior of Case
– Gas Cutting of Chamber??
– Case may show no outward signs of problems prior to firing



https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2019/armament/SiewertTutorial5.pdf

 

[bozo699]

Original Case Material: 70% Copper, 30% Zinc (View attachment 1332383260 Alloy)
• Susceptible to Stress Corrosion Cracking (season cracking)
– Originally Observed by British in India on Brass Cartridge Cases Stored in
Stables & Exposed to Horse Urine
– Caused by combination of material, residual stress & corrosive atmosphere
– Residual stress caused by forming processes
– Corrosive atmosphere from nitrogen bearing compounds in propellant
– Aggravated by “dezincification” of brass during processing
– Causes internal case wall split that propagates to exterior during firing
– Gas Wash on Exterior of Case
– Gas Cutting of Chamber??
– Case may show no outward signs of problems prior to firing



https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2019/armament/SiewertTutorial5.pdf

I’m pretty sure that’s what happened!…. Dave stored his ammo in his horse stall………
Wayne

 

[Dave M.]

I’m pretty sure that’s what happened!…. Dave stored his ammo in his horse stall………
Wayne

I loved this reply Wayne. Actually, I like to pee on my ammo for good luck before every competition. Lol.
Moisés Alou was a great MLB hitter and one of the few that never wore batting gloves, he revealed later in his career that during the baseball season he’d piss on his hands to toughen them up. No wonder none of his teammates wanted to give him high fives.

 

[M-61]

I have 6 pcs of new lapua that like that. Was told that they crack sometimes when forming them. Couple of them you can’t see with out magnify.

Never heard of this before,
"Was told that they crack sometimes when forming them."

 

[DocCarbon]

I’m pretty sure that’s what happened!…. Dave stored his ammo in his horse stall………
Wayne

Although humorous not the point I was making . Simply that corrosion is more susceptible where hot gases are most active and that would be ?. Those photos were for illustration purposes of shoulder corrosion .
I believe DaveM's is more a Torch gas cutting than corrosion ,as in pushing the envelope .

How do You see it ?

 

[bozo699]

Although humorous not the point I was making . Simply that corrosion is more susceptible where hot gases are most active and that would be ?. Those photos were for illustration purposes of shoulder corrosion .
I believe DaveM's is more a Torch gas cutting than corrosion ,as in pushing the envelope .

How do You see it ?

Doc,
I’m sorry I couldn’t resist the post reminded me of something Biged would have posted back in the day!….
How do I see it?……
Well I’m not going to go back through the thread and dissect it but as I recall he had a cutting torch action going from the shoulder up into the neck. In my experience that’s been caused from cases with factory folds “dents” in the shoulder that irons itself out over several firings but fails early in life as these clearly did!… or they fail on the first firing. Other option he had crap!… ie. Powder, bristles, debris off cleaning patches etc left in his chamber!… Dave claimed no way that happened ,… idk I wasn’t there.
Now if it were my brass and I HATE to throw away proven match brass I would go against my normal rants on ultrasonic cleaning which I could write a ten thousand word report on the demerits of squeaky clean brass!….. but I’ll get back on track!… I would clean them in one of those useless ultrasonic cleaners that should be in a mechanic shop for cleaning carburetors and I would clean the remaining 80 some odd cases he said he had of that lot and take my borescope and examine every case!…. If he finds more problem cases I would junk the lot before I had real problems on a firing line!….
That sir is how I really see it but never said anything more than what I did!
Wayne

 

[DocCarbon]

Doc,
I’m sorry I couldn’t resist the post reminded me of something Biged would have posted back in the day!….
How do I see it?……
Well I’m not going to go back through the thread and dissect it but as I recall he had a cutting torch action going from the shoulder up into the neck. In my experience that’s been caused from cases with factory folds “dents” in the shoulder that irons itself out over several firings but fails early in life as these clearly did!… or they fail on the first firing. Other option he had crap!… ie. Powder, bristles, debris off cleaning patches etc left in his chamber!… Dave claimed no way that happened ,… idk I wasn’t there.
Now if it were my brass and I HATE to throw away proven match brass I would go against my normal rants on ultrasonic cleaning which I could write a ten thousand word report on the demerits of squeaky clean brass!….. but I’ll get back on track!… I would clean them in one of those useless ultrasonic cleaners that should be in a mechanic shop for cleaning carburetors and I would clean the remaining 80 some odd cases he said he had of that lot and take my borescope and examine every case!…. If he finds more problem cases I would junk the lot before I had real problems on a firing line!….
That sir is how I really see it but never said anything more than what I did!
Wayne

That's definitive and I can't disagree ,except with regards to ultrasonic cleaning . As with many things in life it generally has to do with how one uses the tools . If I were doing the exam ,I'd cut the torch case length wise on all #3 along another axis ,so as to see clearly inside the worthless cases .
Either way I'd want to SEE inside those cases .

 

[bozo699]

That's definitive and I can't disagree ,except with regards to ultrasonic cleaning . As with many things in life it generally has to do with how one uses the tools . If I were doing the exam ,I'd cut the torch case length wise on all #3 along another axis ,so as to see clearly inside the worthless cases .
Either way I'd want to SEE inside those cases .

No matter how you use a ultrasonic cleaner it removes all the carbon out of your necks which is extremely important to remain in The neck!… Imperial makes dry neck lube but nothing works as well as the carbon left behind!…pretty brass has never ever won a match but consistent seating force has and does!
Wayne

 

[Dave M.]

Although humorous not the point I was making . Simply that corrosion is more susceptible where hot gases are most active and that would be ?. Those photos were for illustration purposes of shoulder corrosion .
I believe DaveM's is more a Torch gas cutting than corrosion ,as in pushing the envelope .

How do You see it ?

I wish I had some explanation for it. That piece of brass had about 15 firings on it so it didn’t owe me anything….I kept it because it was so unusual.

 

[Scott-ak]

The bottom of the crack is interesting. Almost looks like it was center punched. A ding perhaps. Not sure that had anything to do with it, just seems odd

You made me think of when I cut metal with plasma or torch. The cut is so perfect, like metal has been removed rather than displaced from a split caused by pressure, except right where it begins, the dimple. I wonder ... is this a flame cut? and if so is there a corresponding line in the chamber wall?

 

[Dave M.]

I wish I had some explanation for it. That piece of brass had about 15 firings on it so it didn’t owe me anything….I kept it because it was so unusual.

The engineer in me always wants a solution for every problem that arises; perhaps I should have just tossed the piece of brass and moved on. It was just so interesting how it looked like it was physically cut with a cut off wheel.

 

[bozo699]

The engineer in me always wants a solution for every problem that arises; perhaps I should have just tossed the piece of brass and moved on. It was just so interesting how it looked like it was physically cut with a cut off wheel.

Dave, I thought you had two or three or four cases it did the same thing?
Wayne

 

[Firearmsunlimited]

I'm thinking that you have reached the point where the brass has reached the end of its life span. Like bbl's, I figure that brass has a point where it's done.....it's a consumable .....as much as I hate to dispose of brass, if it has given great results on target....it is more than worth the replacement cost.....rsbhunter

Nah, his brass just has worms.

 

[searcher]

No matter how you use a ultrasonic cleaner it removes all the carbon out of your necks which is extremely important to remain in The neck!… Imperial makes dry neck lube but nothing works as well as the carbon left behind!…pretty brass has never ever won a match but consistent seating force has and does!
Wayne

Yes! About every 15 firings on my bolt gun brass - I clean in ultrasonic. I use moly on my bullets to get around the "clean neck". I haven't used a neck brush in 20 years, though I use walnut shells as my tumbling media, which takes off any "fluff' carbon. In my A/R's, I never clean necks. The brass is dead after about 8 firings anyway. And I used to be so meticulous. It takes a long time to see what really matters....

 

[DocCarbon]

No matter how you use a ultrasonic cleaner it removes all the carbon out of your necks which is extremely important to remain in The neck!… Imperial makes dry neck lube but nothing works as well as the carbon left behind!…pretty brass has never ever won a match but consistent seating force has and does!
Wayne

IF one uses a sizing ball or expander that is permanently lubricated and leaves zero residue ,it overcomes any Negative aspect of ultrasonic cleaning . Otherwise I'd agree ,as carbon soot fouling residue is a cushioning lubricant of sorts

I have superior dies and ex-panders as mine are coated with newer space age materials ,which nearly eliminates use of sizing lubes period and the expander's are diamond tough .

We've figured that aspect out a while back . Now what continues plaguing total success is ; The inside of a Die body ,as it's cylindrical smallish in diameter for it's depth and extremely difficult to even disperse material on to . Laser vapor deposition has limitation within those parameters . IF anyone can solve it ,the man I have working on the solution , WILL FIND IT .

 

[bozo699]

IF one uses a sizing ball or expander that is permanently lubricated and leaves zero residue ,it overcomes any Negative aspect of ultrasonic cleaning . Otherwise I'd agree ,as carbon soot fouling residue is a cushioning lubricant of sorts

I have superior dies and ex-panders as mine are coated with newer space age materials ,which nearly eliminates use of sizing lubes period and the expander's are diamond tough .

We've figured that aspect out a while back . Now what continues plaguing total success is ; The inside of a Die body ,as it's cylindrical smallish in diameter for it's depth and extremely difficult to even disperse material on to . Laser vapor deposition has limitation within those parameters . IF anyone can solve it ,the man I have working on the solution , WILL FIND IT .

Doc,
Everyone has a preference I guess and I’m not trying to push my way as I have no world championships under my belt for bragging rights however why would anyone leave lube in your case neck for powder to hang up on and if you remove it your back to step one metal to metal surface which in my experience causes cold weld clickers , inconsistent velocities and so on. For me according to my K&M force seat restoration gauge I get the most consistent bullet seating force with carbon left in my necks lightly brushed the same on every case.
Everyone else’s mileage may vary.
Wayne

 

[DaveDowd]

6 dasher
3048fps MV, 33.1g RL-15, Berger 105g VLD target.
Lapua 6BR brass fire formed to 6 dasher. Shooting normal load at outside temp of 30F this morning in a 600 yard F-Open competition. Same load for the last 1250+ rounds.
12 firings on this brass. Annealed after each firing. Full length sized with a Whidden gun works bushing die (.265” bushing) .271” chamber neck and .2685 loaded round. Have never lost a single piece of brass due to cracks and I inspect 100% of my brass before reloading. Threw a”9” this morning that was 4.5” low and 5.5” left of the rest of my shots. So I put that piece of brass underside down in my loading box. This is what I found when I got home and inspected my brass….
View attachment 1330478View attachment 1330479

Crack is so perfectly vertical that it looks like it was cut with a dremmel wheel. You can see the carbon blowout all around the crack.
Dave

You may want to check your neck clearance. Just a possibilit. Dave