Salt Bath Annealed Necks collapse during seating

[Texas10]

These were out of a batch of 200 once fired Hornaday brass, sized, annealed via salt bath method ( 6 seconds at 1000 F) trimmed, chamfered, SS cleaned all in one continuous operation. Then I loaded 125 A-Maxes in 6.5 CM with no issues, but when I pulled out a nearly empty box of 142 SMK's to load, this happened.

So I moly coated the necks and had good luck getting them to seat, and when I opened the new box of 142 SMK's they seated with no problem.

I am guessing a small amount of oxidation on the mostly empty box was the straw that broke......

Next time someone implies that salt bath annealing does not soften the brass, they should look at this photo. I've loaded a lot of 6.5 CM with 142's and this is the first time I've seen this.

 

[rardoin]

High neck tension and overly soft brass most likely. Ouch!

 

[Poor Shot 65]

probably annealed too long ...

 

[Texas10]

I posted the photo first and added the text later. Limitations of a cell phone!

 

[Bob3700]

View attachment 1124629

These were out of a batch of 200 once fired Hornaday brass, sized, annealed via salt bath method ( 6 seconds at 1000 F) trimmed, chamfered, SS cleaned all in one continuous operation. Then I loaded 125 A-Maxes in 6.5 CM with no issues, but when I pulled out a nearly empty box of 142 SMK's to load, this happened.

So I moly coated the necks and had good luck getting them to seat, and when I opened the new box of 142 SMK's they seated with no problem.

I am guessing a small amount of oxidation on the mostly empty box was the straw that broke......

Next time someone implies that salt bath annealing does not soften the brass, they should look at this photo. I've loaded a lot of 6.5 CM with 142's and this is the first time I've seen this.

Cant imagine the neck tension it took to collapse those shoulders. Would have to guess that when seating those bullets that something didn'tfeel right. I soft seat all my bullets and if the seating pressure was different/ higher than the rest, I stop and find out what the problem is. Run my expanding. Mandrel into the case and feel the fit between neck ID. And mandrel. Pull the bullet and measure the bulletOD. What was different about that bullet n case? I just usea flame anealer but have never experienced overanealing having that type of result.
If indeed it was the salt bath method that caused the problem, I know what I would change immediately in my loading process.
Bob

 

[Webster]

View attachment 1124629

These were out of a batch of 200 once fired Hornaday brass, sized, annealed via salt bath method ( 6 seconds at 1000 F) trimmed, chamfered, SS cleaned all in one continuous operation. Then I loaded 125 A-Maxes in 6.5 CM with no issues, but when I pulled out a nearly empty box of 142 SMK's to load, this happened.

So I moly coated the necks and had good luck getting them to seat, and when I opened the new box of 142 SMK's they seated with no problem.

I am guessing a small amount of oxidation on the mostly empty box was the straw that broke......

Next time someone implies that salt bath annealing does not soften the brass, they should look at this photo. I've loaded a lot of 6.5 CM with 142's and this is the first time I've seen this.

Someone on this website quoted AMP as saying salt bath cannot anneal. AMP does have data to show it doesn't anneal, I have read it??? Try queezing the neck on a 3 sec and 6 sec anneal wih pliers. See if there is a difference. A crude test but it will identify a big loss of hardness. If the neck is really soft you can with little presure from pliers sqeeze the neck slightly oval or completly shut. Do a few cases and you get a feel for it. Use junk cases. It's been a while but I think I could move the case neck 10-20 thou with my fingers on a case I got bright red.

Cannot rember the details but many years ago I collapsed a shoulder like yours on an un-annealed case. Cannot remember what happened but it only happened once in 45 years.

 

[Murray Brook]

@Texas10 So true about your comment on salt bath anneling. I can't figure out how some will say the the neck isn't altered, but if you leave it in the bath too long you will ruin the case head from the heat of the bath liquid.

 

[riflewoman]

Someone on this website quoted AMP as saying salt bath cannot anneal. AMP does have data to show it doesn't anneal, I have read it??? Try queezing the neck on a 3 sec and 6 sec anneal wih pliers. See if there is a difference. A crude test but it will identify a big loss of hardness. If the neck is really soft you can with little presure from pliers sqeeze the neck slightly oval or completly shut. Do a few cases and you get a feel for it. Use junk cases. It's been a while but I think I could move the case neck 10-20 thou with my fingers on a case I got bright red.

Cannot rember the details but many years ago I collapsed a shoulder like yours on an un-annealed case. Cannot remember what happened but it only happened once in 45 years.

Salt bath at 1000 will anneal. That’s close to a dull red in a darkened room temp.

Also 6 seconds at 1000F in the Salt is a long time. The neck should be fypulky annealed in 2 or 3.

 

[Dusty Stevens]

Dont shoot those and ditch the salt bath would be my suggestion at this point

 

[Tarmacshooter]

I thought the temp was supposed to be a lot cooler with that method.

 

[mikecr]

SS cleaned

So I moly coated the necks and had good luck getting them to seat, and when I opened the new box of 142 SMK's they seated with no problem.
I am guessing a small amount of oxidation on the mostly empty box was the straw that broke

You didn't notice the extra seating forces needed to collapse shoulders?

6sec @ 1kdeg doesn't fully anneal anything.

 

[10at6]

Looks like he sized them before annealing per the OP. Hint

 

[Texas10]

I suspect that I had the salt bath filled a bit too deep and covering the whole shoulder area. Usually I have it set to about half way up the shoulder, and 6 seconds (it's actually 5 as I start counting with 1 instead of 0) has always worked well at 1000 F. Live and learn.

As for feel during seating, there was some difference, but not a lot compared to the 125 I seated today and 75 before, along with some 142's previously. Strange that two in a row of the last few bullets in a box did this. I later seated 142's and 130 OTM Bergers with no issue, tho I did lube the necks after trying a few dry just to see how they'd do. They seated slicker than snot with the necks lubed with Moly. Think I may start going that route. We'll see how they shoot.

Over heating the head is not possible without deliberately trying. I left a test case in the bath for 5 minutes to see if it'd soften the head. I couldn't tell any difference but then I didn't have a Rockwell gage. Not exactly a scientific methodology.

FWIW: I once made the mistake of seating a 6.5 bullet in my 6BR case after annealing this method. Slid in without a hint of trouble, only caught it when I measured the CBTO and it was way off. Scratched my head a few times and then saw the label on the box. Oooops!

 

[Texas10]

Looks like he sized them before annealing per the OP. Hint

I have noticed that the neck size tends to change slightly during annealing. Might have to rethink that procedure if I run into this again.

What sayeth the brain trust? Anneal before or after sizing?

 

[Murray Brook]

No expert by any means, but what I do is deprime my cases then anneal and the rest of the case prep afterwards. JMW

 

[Ringostar]

If you anneal first, you should get more consistent case sizing.

 

[mikecr]

The recent AMP article was all about proving that SBA does not fully anneal. Well I don't know why anyone would want to fully anneal, much less pay so much to do that.
But given that SBA does not fully anneal, and having dip annealed for over 30yrs I know it doesn't, it makes no sense to me that shoulders could be collapsed with bullet seating -without seriously excess forces applied.

Perhaps the Hornaday brass was fully annealed by the mfg., added to excess seating friction & forces applied.

 

[jaygorski]

1000F is too hot, should be in the 850F area.

 

[jaygorski]

View attachment 1124629

These were out of a batch of 200 once fired Hornaday brass, sized, annealed via salt bath method ( 6 seconds at 1000 F) trimmed, chamfered, SS cleaned all in one continuous operation. Then I loaded 125 A-Maxes in 6.5 CM with no issues, but when I pulled out a nearly empty box of 142 SMK's to load, this happened.

So I moly coated the necks and had good luck getting them to seat, and when I opened the new box of 142 SMK's they seated with no problem.

I am guessing a small amount of oxidation on the mostly empty box was the straw that broke......

Next time someone implies that salt bath annealing does not soften the brass, they should look at this photo. I've loaded a lot of 6.5 CM with 142's and this is the first time I've seen this.

Hornady just annealed these and you did it again so soon, why I have to ask? I let my Hornady brass go 5-10 firings before I anneal them again.

 

[jthor]

1000F is too hot, should be in the 850F area.

Two words for simple thermodynamics, heat transfer. The rate at which the brass heats is faster when the delta in temperature between the brass and the heat source is large. Once that delta becomes smaller the rate at which the brass heats up becomes slower. Furthermore, just because you put something in a hot liquid for 6 seconds does not mean, at all, that it has reached the temperature of the liquid.