Do I throw away this whole lot of brass?

[Mike Matteson]

For 1: The people that are shooting long range matchest are full length sizing there cases every time. 2. I would be throwing those cases in the recycling bend sometime back. You are screwing up you chamber. Nothing said about annealing the cases. (That doesn't have much to do with case separations,but) I would say either your dies aren't adjusted correctly or your head space is off. Past time to go to a gunsmith and have it checked out. With what you are showing, it would appear that you are not checking for base separation after firing the cases. You can get a larger paper clip and sharpen one end. Put a very short 90dgr turn on it and straighten out the rest of the paper clip. put it inside each case to the base and move up and down about 1/4" around the inside of the base. It your point catches moving around the case base inside it's showing starting head separation. Time to recycle that case.

 

[Calvin45]

hmm ... not hot loads and an ackley chamber makes me think that the headspace might be a bit on the long side (excessive) ... have you checked it?

Are you full length sizing each time? ... and if so, I'd be interested to know how much it is getting set back each time. If headspace is at or near 'minimal' then I'd say this brass maybe shouldn't be used anymore ...

FYI - I've got cases with lots higher number of reloads on them and the case heads are in great shape ... my issues typically begin with split necks (for cartridges in which I am using traditional neck and/or full length sizing methods) ...

Yeah something's not right here if we're getting legit head separation on five firings, with a sharp shouldered case to boot!

 

[Hugnot]

Most of the above seems on track.

I see a shiny ring, probably .05" high, just over the extractor cut, might this be an indication of a bad brass lot? If there were tight forced brass crush fits inside the chamber just above the extractor cut but just above that point thin brass, a case rupture might occur at that point independent of head-space. The tight solid base just above the extractor cut would not expand but the thinner area just above that point would be subjected to stretching as the brass flowed forward in successive firings (tension) exceeding elastic limits of the brass. Sizing the fired cases in a F/L die would reveal the wider diameter brass area as a polished ring as the die pushed into the fatter ring. Rupture points (rings) occurred just above the polished fat ring. Sectioning cases length wise might show this - like a solid base having no taper to thinner brass above. "U" shaped inside. .

Was extraction upon firing difficult. Were the cases FF inside the chamber to make AI brass?

I like minimum head-space brass fits and avoid bumping brass as much as possible.

Sure good advice to toss the works - repeated blasts of hot gas at some 60K psi would eat up your chamber.

I had this problem with some .22-.250 brass in a tight chamber and noticed hard extraction & a similar polished ring upon sizing.

 

[skipglo]

I have been messing with some brass that I know is on it's last loading. I have a bunch more of it prepped and ready to load but maybe 10% of them are coming out of the chamber with partial case head separation. Should I have quit using it the first time this happened to a single piece or is ok to run through the rest of of the lot before trashing it? It's been fired 5 times, Nosler brass 280 AI. I am not pushing it that hard and the gun has a tight chamber.

View attachment 244632

I'd toss it! Long slow process to get the stuck case out!

 

[crystalgayleguy]

you could have gotten a bad batch of brass

 

[Troutslayer2]

Most of the above seems on track.

I see a shiny ring, probably .05" high, just over the extractor cut, might this be an indication of a bad brass lot? If there were tight forced brass crush fits inside the chamber just above the extractor cut but just above that point thin brass, a case rupture might occur at that point independent of head-space. The tight base just above the extractor cut would have no space to expand but the thinner area just above that point would be subjected to stretching as the brass flowed forward in successive firings (tension) exceeding elastic limits of the brass. Sizing the fired cases in a F/L die would reveal the wider diameter brass area as a polished ring as the die pushed into the fatter ring. Rupture points (rings) occurred just above the polished fat ring. Sectioning cases length wise might show this.

Was extraction upon firing difficult. Were the cases FF inside the chamber to make AI brass?

I like minimum head-space brass fits and avoid bumping brass as much as possible.

Sure good advice to toss the works - repeated blasts of hot gas at some 60K psi would eat up your chamber.

You might be on to something. Extraction has never been tough. I just pulled pieces of 1x fired Peterson out of the tumbler. There is a faint halo/ring in this same spot. I am going to take this thing to the smith who chambered it along with my die and some pieces of brass and see what they think.

 

[freddiej]

the brass tells me there is something very wrong with that chamber. if this is the 5th loading and partial case head separation happens I would look into a case micrometer and find out what the heck is your head space length and lengthen you reloading die accordingly. the brass as it sits is scrap with the chamber being as long as it is.. I am guessing somewhere between 0.009" to 0.011". 0.012" it would have come apart. Best advice take the brass and the gun to a gunsmith and have him check the chamber and the brass stretch you are getting.

 

[longestrange]

3000 psi gas directly in front of a scuba tank valve will penetrate your skin and cause serious damage. Small 3000 psi hydraulic hose leaks will do the same, and can kill you quite dead. You are dealing with hot 60,000 psi gas here. Although there are various safeguards built into rifles, if it manages to find/break open a path to freedom you'll wind up in the hospital. I wouldn't even think about using that rifle or ammo without getting the problem diagnosed by a competent smith and would not trust just the guy who chambered it either. Nobody can sit here on the net and diagnose something like that, anything could be an issue.
Edit: Just for reference, if you grip a revolver incorrectly it can and will cut your thumb off...

 

[LoneTraveler]

Time to scrap that brass. Something is not right. That brass looks like 7MM Sharp and Hart Brass shot in a Shultz and Larson rifle after about 3rd loading.

I would take the Rifle, Sizing Die and the cases back to the smith who assembled it.
If the action was blueprinted the bolt may be locking on the bolt handle instead of the lugs. SWAG
Or the headspace is out of specs. May have to set the barrel back or new barrel.

 

[PNWdude67]

Are you annealing your brass? Maybe the neck and shoulders are work hardened and pulling on softer brass further down the case. I haven't yet gotten into annealing but with ammo shortage I'll need to make my brass last. I think most competitive shooters anneal every time, and reuse their brass many times.

FL size every firing. Bump .003. Anneal every firing not for the purpose of extending brass life, but for enhancing neck tension consistency. Really, just ensures all cases are at the same phase of "hardening" by annealing each cycle. We have gone through batches every other or third firing and they last just as long. To extend brass life, load at lower pressures velocity nodes. Usually, when cases head separate early, before necks crack, its do to a head spacing issue allowing the case to over stretch.

 

[223Rem]

no such thing as partial separation .. scrap it ..

Just like a little pregnant.

 

[Mike Matteson]

FL size every firing. Bump .003. Anneal every firing not for the purpose of extending brass life, but for enhancing neck tension consistency. Really, just ensures all cases are at the same phase of "hardening" by annealing each cycle. We have gone through batches every other or third firing and they last just as long. To extend brass life, load at lower pressures velocity nodes. Usually, when cases head separate early, before necks crack, its do to a head spacing issue allowing the case to over stretch.

That's what I see, but you described it better than me. I only seen it once that back over 50 years ago with a friend rifle. He knew what it was right off. I still think about him, and he been gone a great many years. I do have it with my belted mag, but that over 10 or more firing that I detect base separations starting. Brass is then recycled.

 

[Mikecr]

There was never a reason in reloading to have, much less accept, cracking or separations.

 

[Troutslayer2]

Took it to my guy today. We looked at the reamer print, compared that to measurements taken off the spent brass. Go/No Go/Field Gauges all checked out and the chamber is extremely tight for the cartridge. The consensus is that the Nosler brass is garbage and considering how hard I am running it that maybe I should consider myself lucky to have gotten that many firings out of it. There is nothing wrong with the chamber but I left it there and he's going to polish it and also pin my pic rail.

I've been pushing 168 grain bullets at 2900FPS from a 22" tube and I guess I should probably pay more attention to pressure signs or get used to buying brass. Might keep shooting at that velocity with the Peterson brass and see how well it holds up. The other node with this barrel is way lower.