Gunsmithing Cracking cases- need input

[pell1203]

Explain your annealing process, dwell times, glowing red, melt tempilaq, etc...

Milo, it does not make any difference what annealing process was used. In earlier thread in reloading section, and perhaps somewhere in this thread as well, OP states that all failures occurred inside of three firings and that the brass was bought new and had NEVER been annealed since purchased.

OP, or his brother, has also not reloaded the brass for a fourth time. Failures occurred after third firing.

 

[Long Range 338]

If you could explain as why that is relevant here, we could discuss it. Primers look fine.

In cases of excessive headspace upon firing the primers can back out slightly and look like the primers in the pics. If you observe closely it appears the primers do not appear to be flush or below and the edges of the primers are sharp, not rounded. Also the primers appear to have marks on them from the bolt face.

 

[Milo 2.5]

Milo, it does not make any difference what annealing process was used. In earlier thread in reloading section, and perhaps somewhere in this thread as well, OP states that all failures occurred inside of three firings and that the brass was bought new and had NEVER been annealed since purchased.

OP, or his brother, has also not reloaded the brass for a fourth time. Failures occurred after third firing.

You're right, thanks

 

[Milo 2.5]

In cases of excessive headspace upon firing the primers can back out slightly and look like the primers in the pics. If you observe closely it appears the primers do not appear to be flush or below and the edges of the primers are sharp, not rounded. Also the primers appear to have marks on them from the bolt face.

IME with excessive headspace or too much bump, the case comes apart above the rim, does not blow necks off. Either his brass is junk, or his die or chamber is causing this IMO.
Either way, he needs to quit firing this brass.

 

[eastexsteve]

I know what you're saying and I hesitated to post that picture as it looks worse in the picture than what it actually is.

Just going by the pics from yesterday and today, it looks like:

1. The case mouths to me look like they are starting to round as if the overall case length is long. This will cause the case mouth to bite down on the bullet and cause excessive pressure.

2. The picture from yesterday showing the fired brass appeared to show some shiny belts around the lower end of the cases as if they have some stretch.

3. Those primers look like they are starting to back out and flatten. The top case in the head stamp pic looks like it has an extractor mark at the 12 o'clock position.

Those pictures might be misleading, but all this looks like excessive pressure.

 

[Edds]

If I wanted to purposely load and fire a piece of brass in a manner that would make the neck come off in three firings, I don't know what I would do.

So, based on the information provided, I'm going with faulty brass.

 

[Rocketvapor]

Residual lube on the case ?
Glad the Op bought up all the faulty brass.

 

[Milo 2.5]

Just going by the pics from yesterday and today, it looks like:

1. The case mouths to me look like they are starting to round as if the overall case length is long. This will cause the case mouth to bite down on the bullet and cause excessive pressure.

2. The picture from yesterday showing the fired brass appeared to show some shiny belts around the lower end of the cases as if they have some stretch.

3. Those primers look like they are starting to back out and flatten. The top case in the head stamp pic looks like it has an extractor mark at the 12 o'clock position.

Those pictures might be misleading, but all this looks like excessive pressure.

The primer or primer pocket is still the weakest link, primers would separate from the pocket long before a neck flies off.

 

[abn31c]

Does anyone else think the necks look long?

 

[MrSmith]

If you are using a seating/crimp die check that the die body is adjusted correctly. Should it be to low, or the necks be to long, it would push the neck toward the shoulder and flex that location. With a mic or caliper measure the length of a prepared case before seating a bullet and then after. If there is an appreciable difference find out why. Also mic the diameter of the case body just at the base of the shoulder before and after seating. This is a hard place to measure since there is no repeatable spot to locate to but any large changes, if present, should show up. Should you have access to a case gauge this is an instance where it would come in handy for a quick check.

Also, if the loader is only neck sizing, check how far down the bushing sizes the neck. As above, if the bushing travels to far that would also push the neck toward the shoulder.

Thank you,
MrSmith

 

[morano]

"Residual lube on the case ? "

Or the walls of the rifle chamber not free of oil......

 

[Rocketvapor]

Like yanking the head off a chicken?

 

[SWWI Shooter]

If you are using a seating/crimp die check that the die body is adjusted correctly. Should it be to low, or the necks be to long, it would push the neck toward the shoulder and flex that location. With a mic or caliper measure the length of a prepared case before seating a bullet and then after. If there is an appreciable difference find out why. Also mic the diameter of the case body just at the base of the shoulder before and after seating. This is a hard place to measure since there is no repeatable spot to locate to but any large changes, if present, should show up. Should you have access to a case gauge this is an instance where it would come in handy for a quick check.

Also, if the loader is only neck sizing, check how far down the bushing sizes the neck. As above, if the bushing travels to far that would also push the neck toward the shoulder.

Thank you,
MrSmith

Thanks, I'll forward this on to him to check.

 

[SWWI Shooter]

Does anyone else think the necks look long?

For those that wanted to know the length of the fired cases-they are right at 1.912.

 

[pabrousseau]

take a look inside the neck at neck shoulder juncture for a donut. will a bullet drop through the neck of a fired case? if you are not seating the bearing surface of the bullet as far down as the neck shoulder juncture disregard any thing I have said as it makes no difference if there is a donut.

 

[pabrousseau]

I suppose a fl sizing die could work the brass making it brittle if there is a donut there so let us know either way.

 

[SWWI Shooter]

take a look inside the neck at neck shoulder juncture for a donut. will a bullet drop through the neck of a fired case? if you are not seating the bearing surface of the bullet as far down as the neck shoulder juncture disregard any thing I have said as it makes no difference if there is a donut.

No donut there on fired cases. Also checked the cases that cracked but did not separate. No donuts there either. I hesitate to throw this out there as it is going to open up a whole new can of worms but when he first started to reload these Nosler cases (first loading), he got a few in the first 40 that had the shoulder slightly dented. I don't remember the order but he tried the spray on lube and the kind that you roll on a mat. He is now using powdered graphite and hasn't had issues since switching to that.

 

[MarinePMI]

Tight chamber neck and excessive shoulder bump? Something is causing the neck to adhere to the chamber wall, while the rest of the case is moving back during ignition IMHO...

 

[SWWI Shooter]

Tight chamber neck and excessive shoulder bump? Something is causing the neck to adhere to the chamber wall, while the rest of the case is moving back during ignition IMHO...

Interesting theory and based on my limited reloading knowledge, that would account for it. Thanks.

 

[smoothy8500]

If you could explain as why that is relevant here, we could discuss it. Primers look fine.

Primers backing out upon firing could indicate excessively re-sizing the case, more than the 2-3 thou reported by the OP.

 

[Milo 2.5]

Primers backing out upon firing could indicate excessively re-sizing the case, more than the 2-3 thou reported by the OP.

In your history of reloading, does excessive bump result in neck separation? Topic is neck separation.

 

[Milo 2.5]

Interesting theory and based on my limited reloading knowledge, that would account for it. Thanks.

Just say this is the case, find a way to cast your chamber so you can get some measurements, unless you can find the reamer diagram. I forgot what rifle it is.

 

[SWWI Shooter]

Just say this is the case, find a way to cast your chamber so you can get some measurements, unless you can find the reamer diagram. I forgot what rifle it is.

It is a Tikka CTR.

 

[Milo 2.5]

It is a Tikka CTR.

I'd have a hard time believing it is a tight neck chamber then.

 

[MarinePMI]

I'd have a hard time believing it is a tight neck chamber then.

Agreed. Being a hammer forged barrel means that it usually entails the chamber as being part of the forging mandrel. Kind of hard to screw up a chamber that way (tight neck)....

 

[Long Range 338]

In your history of reloading, does excessive bump result in neck separation? Topic is neck separation.

Why are you policing the topic and discussion here so hard? The general discussion is about brass and we are merely pointing out indications of pressure. If a case is oversized and can move enough to bump a primer, would this not allow for stretching in the head, shoulder, and neck? If you have the answers I’m certainly happy to sit back and be educated. My opinion is that in the sharing of ideas and experiences we all grow.

 

[Milo 2.5]

Why are you policing the topic and discussion here so hard? The general discussion is about brass and we are merely pointing out indications of pressure. If a case is oversized and can move enough to bump a primer, would this not allow for stretching in the head, shoulder, and neck? If you have the answers I’m certainly happy to sit back and be educated. My opinion is that in the sharing of ideas and experiences we all grow.

The op wants to know why his necks are coming apart. If I had the solution, I'd fill him in.
So, if he had bumped his brass back into the dark ages and fired it, just the slam into the bolt face will flatten a primer, maybe gas it too(escape),maybe force brass to minorly flow into ejector hole, does this constitute pressure? NO, it means he oversized his brass, and the back end of the brass is going to take the punishment. Primers are not the best indication of pressures. Have you ever tried to fireform brass w/o jamming a bullet or made a false shoulder? <Once again here, the back end of the brass takes the hit, the shoulder gets pinned, expansion goes the opposite way. Case head separation is imminent.
I am not sure if by design, but brass acts as a buffer or shock absorber in your chamber, and tell me, when have you seen necks or shoulders beat up from even extreme over pressure loads, it does not happen. Primer pockets and case heads bear the brunt of it. Even if this guys case mouths could not open fully, the primer will get blown out before a neck separates.
So you go ahead and sleuth the primer that has a radiused edge yet, and magnify the pic to look for a crescent shape mark on a case head.
The op needs to boresope both his die and his chamber, or have someone qualified do it. Or some Sat morning, go to his brothers, open some new brass and continually load the same 10 cases in the same fashion as has been done and rule brass out.
EDIT: We have a reloading forum with many discussions on pressure, overpressure, etc...

 

[smoooth1]

 

[Milo 2.5]

View attachment 7009142View attachment 7009143

OMFG, does 3 firings constitute work hardening?

 

[Milo 2.5]

SWWI Shooter , I'm out, if I can be of assistance, pm me

 

[SWWI Shooter]

To keep anyone interested updated; I did arrange to have someone check the rifle chamber with go/ no go gauges but it won't be until at least tomorrow. I called Nosler today and they requested that I send them in. I also decided to pull a couple bullets from my remaining loaded cartridges with brass that had only been fired twice. Well one came out fine but the second not so well.

 

[Milo 2.5]

To keep anyone interested updated; I did arrange to have someone check the rifle chamber with go/ no go gauges but it won't be until at least tomorrow. I called Nosler today and they requested that I send them in. I also decided to pull a couple bullets from my remaining loaded cartridges with brass that had only been fired twice. Well one came out fine but the second not so well. View attachment 7009235

If you set the ball rolling with Nosler, wait for their answer, need to eliminate things one at time now. Request a speedy answer.

 

[pell1203]

Yikes!!! Please make this be bad metallurgy. Staying tuned in for the answer.

 

[SWWI Shooter]

One other thing that I forgot to add in my last post. My brother checked some of my loaded and fired rounds and it looks like he was bumping them about 4 thou as opposed to the 2-3 noted earlier.

 

[SWWI Shooter]

Yikes!!! Please make this be bad metallurgy. Staying tuned in for the answer.

I have a hard time seeing it any other way. No matter what he is doing when loading them, it would be hard to imagine destroying them that quickly. I guess the good thing is that when it gets sorted out, we will all learn something and I don't have a once in a lifetime hunt around the corner so I have time.

 

[pell1203]

SWWI Shooter, I tried looking through the entire thread and could not find the following information anywhere. It might help to illuminate the discussion if we knew the following:

1. Neck size of fired case.
2. Neck size of neck sized case before loading.
3. Neck size of loaded round.

Trying to determine how much the brass is being worked by loading process. Also, I’m still not 100% sure if a full size or bushing die was being used to neck size. If a bushing die is being used, what bushing size are you using.

 

[Edds]

To keep anyone interested updated; I did arrange to have someone check the rifle chamber with go/ no go gauges but it won't be until at least tomorrow. I called Nosler today and they requested that I send them in. I also decided to pull a couple bullets from my remaining loaded cartridges with brass that had only been fired twice. Well one came out fine but the second not so well.

Can you post a picture of the pulled bullet?

 

[Long Range 338]

Assuming the problem is with the neck area, could carbon build up in the throat cause this or similar issue?

 

[ShooterwithNoName]

Agreed if you can get those measurements above that may help solve this. Casting your chamber isnt a bad idea either, just good info to have even if the chamber is ok.

Tagged... also interested in what you find.

 

[Edds]

If I wanted to purposely load and fire a piece of brass in a manner that would make the neck come off in three firings, I don't know what I would do. .......

I have thought of a way I might could make this happen. I would push the shoulder back too far, seat the bullet where it was jammed into the lands, and, as a bonus, crimp the case mouth onto the bullet.

 

[MarinePMI]

AS Milo pointed out, if you did that, typically the case head would take the brunt of the expansion. The case would normally separate at the base of the casing, not the neck.

This has definitely been an odd problem in this thread...

 

[Jake the dog]

I posted this in the original thread in the reloading forum, but it appears dead over there now. I have my first 6.5 CM, and will be reloading for it soon, so I'm very interested in how this comes out. My question for those wiser than me. If the neck is being undersized with a bushing die, and then expanded with a mandrel, could that be overworking the corner where the neck and shoulder meet? Probably completly off the wall, but I wonder if it's possible.

 

[eastexsteve]

To keep anyone interested updated; I did arrange to have someone check the rifle chamber with go/ no go gauges but it won't be until at least tomorrow. I called Nosler today and they requested that I send them in. I also decided to pull a couple bullets from my remaining loaded cartridges with brass that had only been fired twice. Well one came out fine but the second not so well. View attachment 7009235

I noticed the top of the neck on this case has a very uniformly square edge on it. This is unlike the other pics of cases that you have fired. Most of those appear to have a roll on the outer edge as if they are being forced against the top of the chamber. Are you sure you don't have a length problem going on somewhere?

 

[JimLee]

Why are you policing the topic and discussion here so hard? The general discussion is about brass and we are merely pointing out indications of pressure. If a case is oversized and can move enough to bump a primer, would this not allow for stretching in the head, shoulder, and neck? If you have the answers I’m certainly happy to sit back and be educated. My opinion is that in the sharing of ideas and experiences we all grow.

The dude is a grade A asshole and can't help himself, that's why.

 

[Milo 2.5]

The dude is a grade A asshole and can't help himself, that's why.

You still trying to inflate your significance here?

 

[Rocketvapor]

The dude is a grade A asshole and can't help himself, that's why.

Two pages and you jump in with name calling?

 

[Milo 2.5]

I posted this in the original thread in the reloading forum, but it appears dead over there now. I have my first 6.5 CM, and will be reloading for it soon, so I'm very interested in how this comes out. My question for those wiser than me. If the neck is being undersized with a bushing die, and then expanded with a mandrel, could that be overworking the corner where the neck and shoulder meet? Probably completly off the wall, but I wonder if it's possible.

A die with a bushing will never actually reach the junction like a regular die can. There is a ledge that holds the bushing in place, keep from dropping into die body, plus bushings are radiused some.

 

[SWWI Shooter]

I noticed the top of the neck on this case has a very uniformly square edge on it. This is unlike the other pics of cases that you have fired. Most of those appear to have a roll on the outer edge as if they are being forced against the top of the chamber. Are you sure you don't have a length problem going on somewhere?

I don't think so as the cases are trimmed as needed but I guess I couldn't guarantee it. The fired cases that I measured were all right at 1.912 if that helps. Obviously, the chamber length is the part of the equasion that I don't know.

 

[JimLee]

Two pages and you jump in with name calling?

Sure, when assholes start attacking others for having an opinion. There's plenty of damn good reloaders on here, milo isnt the god his overinflated ego tells him he is, he doesn't get free reign to jump on others peoples shit without being called out for it. And honestly, you can go fuck yourself also.

 

[Rocketvapor]

Thanks for setting me straight.
I'm obviously out of my league here.