Strange case failure

[Bill K]

What did you figure out was the problem ? Usually breaks like this, anywhere on the case is caused by sizing/bumping/etc the case too often and causing a head space issue.

 

[RustyInBend]

I checked out at "7-8 firings" and "... not annealed". I know some guys don't believe in annealing, but just like "climate change" ... not believing in it won't make the problem go away.

 

[Paul's Black Rifles]

I haven’t seen the neck portion, it was still stuck in his chamber when he left.

Cerrosafe should capture the broken neck.
Or run the original reamer back in lightly.
Or so I've heard.
Paul

 

[Shooter13]

I haven’t seen the neck portion, it was still stuck in his chamber when he left. The break in the case body was pretty clean. I think we’ve figured it out. Thanks everyone!

Okay, you have it figured out................so what was it?

 

[bugman]

You are overthinking this.
rotate a bronze brush in that is a caliber larger. All that matters is it is tight, and the tighter the better.
Use a pistol rod and you will have more control.
If it doesn't pull on the first try or two, spray some brake cleaner on the brush. rotate it until you feel part of the brush is in front of the separated neck, then pull straight back....hard and fast.

 

[Doug Beach]

He didn’t have any trouble getting the severed case neck out of his chamber, I just didn’t see it.
I’m pretty confident the issue was caused by the sizing die change discussed in posts 11 & 14.

 

[Dgd6mm]

While we’re on the subject, what size brush would you use to fish that 6 neck out with?

 

[Dgd6mm]

You are overthinking this.
rotate a bronze brush in that is a caliber larger. All that matters is it is tight, and the tighter the better.
Use a pistol rod and you will have more control.
If it doesn't pull on the first try or two, spray some brake cleaner on the brush. rotate it until you feel part of the brush is in front of the separated neck, then pull straight back....hard and fast.

 

[Doom]

Failure at this point is a fatigue issue due to cold working the brass. As the brass hardens with resizing the tensile strength increases but the fatigue strength and number of cycles decreases hence the comments related to annealing/stress relieving. Also the brass becomes more susceptible to stress corrosion cracking. In this case it's likely the brass being sized in the FLS die is partially to blame since these dies overwork the neck in particular compared to a bushing die.

 

[gunsandgunsmithing]

Just a fresh brush of the same caliber is usually all that's needed here. Nothing really holding on to the broken neck.
It's like it's just setting there. YMMV, and the cerrosafe trick will typically get a really tough one out but just very rarely needed.

 

[Dave M.]

Without detailed information and maybe even with it, any diagnosis might be just supposition.

However, given the failure mood, I will take a stab at it, if the case was annealed, I would suspect over annealing causing the brass to exceed its elastic limit.

I seriously doubt this is a case of over annealing. I’m speaking from experience having purposely over annealed cases and judged their performance against ones that were properly annealed. I would lean more to a case of servereky overworked and hardened brass, with NO annealing whatsoever.

 

[Dave M.]

What did you figure out was the problem ? Usually breaks like this, anywhere on the case is caused by sizing/bumping/etc the case too often and causing a head space issue.

Or too much bump causing excessive headspace combined with a fast, near max charge weight.

 

[K22]

I seriously doubt this is a case of over annealing. I’m speaking from experience having purposely over annealed cases and judged their performance against ones that were properly annealed. I would lean more to a case of servereky overworked and hardened brass, with NO annealing whatsoever.

What got my attention was his description, "clean break". Like most, I have experienced fatigue failures but never a "clean break". Also, never had a separation in the neck / shoulder area even after loading 15 to 18 times with a F/L die and no annealing.

However, you probably have forgotten more than I'll ever know about annealing, so I trust your assessment in ruling out annealing as the root cause.

 

[Fire Dog]

I’ve never annealed, and I’ve never had any kind of case neck failure, with cases reloaded well past 10 times.
I’ve been reloading for over 30 years, with 10’s of thousands of rounds fired in competition, and I’ve never seen this particular failure, in my brass, or anyone else’s. Just peaked my curiosity, is all.

The only brass I have ever had fail at the shoulder leaving the shoulder and neck in the chamber was on very old {brittle?} 30-06 cases that had been fired through a Garand multiple times then used in a bolt gun and that is where the case failed..
Age embrittlement and no annealing + a lot of expansion through firing and contraction due to sizing seemed to be the cause as the same batch also was splitting necks 3-5 out of 10 rounds.

 

[ronemus]

While we’re on the subject, what size brush would you use to fish that 6 neck out with?

I use a nylon brush so I don't scratch anything by reversing it. I've used the same caliber and oversized successfully.

 

[divingin]

My bet is just a case of work hardened brass.

I'd second that.

Way back when, a guy who retired from shooting gave me his "match brass" - stuff that he used in fun matches with his buddies 5 or 10 years prior. Running it through a sizing die resulted in over half of it tearing the neck off with the failure point being from just below the shoulder to the as high as the neck/shoulder junction (there may have been a couple that failed along the neck itself - don't remember now.)

That brass now resides at the bottom of my recycling bucket.

 

[Fire Dog]

I'd second that.

Way back when, a guy who retired from shooting gave me his "match brass" - stuff that he used in fun matches with his buddies 5 or 10 years prior. Running it through a sizing die resulted in over half of it tearing the neck off with the failure point being from just below the shoulder to the as high as the neck/shoulder junction (there may have been a couple that failed along the neck itself - don't remember now.)

That brass now resides at the bottom of my recycling bucket.

I might add my 2 cents worth and say that through multiple firings the brass at the shoulder and neck gradually erodes and thus weakens and when age also factors in you can almost guarantee case failure….

 

[gunsandgunsmithing]

I might add my 2 cents worth and say that through multiple firings the brass at the shoulder and neck gradually erodes and thus weakens and when age also factors in you can almost guarantee case failure….

How does one measure or quantify that erosion?

 

[Fire Dog]

How does one measure or quantify that erosion?

A ball micrometer reading on a new case carried through multiple firings will keep track of the neck.
Not sure how to measure the inside thickness right at the shoulder junction... Perhaps some sort of micrometer device with an adjustable rod to enter the neck and then be deployed to the edges?
X-ray would also be able to check on density but that seems to be beyond anyone normally unless you were in the medical or some sort of certification business.

 

[wildcat3d]

Is this one of those 'Neck Size Only' cases?
No bump.
7 or 8 times without annealing?
Where would you expect the case to fail?

primer if ya doing it right.. ;-)