Buckled case during expander mandrel 6.5cm

[Allthewatts]

Well had a first that I could use some help with. I just started annealing, and on my second batch. I had two cases out of 50 buckle on the case shoulder after FL size, during expanding the neck with an expander mandrel.
Hornady brass, (doesn't happen with my alpha brass), Forster FL sizer with expander ball removed. 21st century carbide expander. Any thoughts?

 

[straightshooter1]

Well had a first that I could use some help with. I just started annealing, and on my second batch. I had two cases out of 50 buckle on the case shoulder after FL size, during expanding the neck with an expander mandrel.
Hornady brass, (doesn't happen with my alpha brass), Forster FL sizer with expander ball removed. 21st century carbide expander. Any thoughts?

What are you using to anneal your cases?

Are you cleaning the cases after annealing? If not, it's a good idea to do so in order to remove the sticky oxidation layer that forms on the surface. Or, use some lube inside the neck before inserting the expander mandrel.

You may want to review your annealing procedure, as you may be annealing the shoulders and below too much (making that area too soft). . . ???

I also use a Forster FL sizer for my .308 cases without the expander ball. But I also had Forster hone the die so it doesn't reduce the neck so far that my expander mandrel doesn't have to do so much work on the neck. And that also helps retain good concentricity.

. . . some of my thoughts.

 

[Allthewatts]

I likely underlubed the mandrel, I did not clean post annealing, so that's likely part of the issue. I've never had anything like this, so was scratching my head a bit.

I use an induction annealing machine that I made. very capable of varying case position, so something I could look into.

 

[KnowNothing256]

My question is: is the mandrel die screwed in too far? It’s very easy to run that die too low, so the mandrel does its job, but then the case mouth bottoms out inside the die. The force required to run the mandrel is minimal, for you to collapse shoulders means you’re really leaning into the press and that’s a good sign something’s wrong on this step.

ETA: Here’s a decent way to avoid the issue I describe. Remove the mandrel from the die, and back the die all the way out. Run a case up until the ram hits full travel, then screw the die in until you feel it bottom out on the case (with 6.5 CM and the standard mandrel body from 21st Century the die won’t hit the shell holder, it’ll hit the case mouth first). Then back the die out a full turn, reinstall the mandrel, and try it.

 

[6.5SH]

The cases look filthy especially inside the necks. Better case cleaning and brushing inside the necks especially post annealing need to be added to your routine.

 

[Allthewatts]

My question is: is the mandrel die screwed in too far? It’s very easy to run that die too low, so the mandrel does its job, but then the case mouth bottoms out inside the die. The force required to run the mandrel is minimal, for you to collapse shoulders means you’re really leaning into the press and that’s a good sign something’s wrong on this step.

ETA: Here’s a decent way to avoid the issue I describe. Remove the mandrel from the die, and back the die all the way out. Run a case up until the ram hits full travel, then screw the die in until you feel it bottom out on the case (with 6.5 CM and the standard mandrel body from 21st Century the die won’t hit the shell holder, it’ll hit the case mouth first). Then back the die out a full turn, reinstall the mandrel, and try it.

I have ran that same procedure. I have 150 thou clearance from the mandrel shoulder

Shockingly, I didn't really notice more force on the cam. I run a short handle, and it was quite easy to fold.

 

[KnowNothing256]

Dang, well that was my guess. Best of luck, curious to hear the final answer.

Yet another ETA: Backtracked and read the annealing process, that's my next thought, that the case is way too soft from being over-annealed. With a DIY kit not sure how you'd know where to stop though, perhaps with external Tempilaq down at the shoulder-to-body junction.

 

[Allthewatts]

The cases look filthy especially inside the necks. Better case cleaning and brushing inside the necks especially post annealing need to be added to your routine.

These cases were cleaned with SS pins in a rotary tumbler for 45min, surfactant and citric acid added as well. I do agree though, there is carbon still on the ID of the neck. Maybe a SS or Nylon brush would be worth wile to do. I haven't heard much of people specifically cleaning the necks, suggestions?

 

[smoooth1]

Definitely need to brush the inside of the necks and (lightly) lube them or the mandrel.

 

[KnowNothing256]

These cases were cleaned with SS pins in a rotary tumbler for 45min, surfactant and citric acid added as well. I do agree though, there is carbon still on the ID of the neck. Maybe a SS or Nylon brush would be worth wile to do. I haven't heard much of people specifically cleaning the necks, suggestions?

If you want the necks cleaned out, just run the tumbler longer. Some folks have had issues with cold-weld if they clean the necks too much, load the rounds up, then don't shoot them for awhile; some leftover carbon in the neck is one way to avoid that, lubing necks is a more obnoxious way to do so.

 

[smoooth1]

Also, not every case is exactly the same. Some will over anneal. as may well be the case (and fitting pun, lol) here.

Those vertical lines inside the necks are not a good sign; that is where the mandrel is sticking.

Congratulations on building your induction annealer!

 

[acudaowner]

raise your die set till it stops doing it you only need to get the die in the neck not down to the flash hole . ps I did the same thing with a couple of pieces while learning how to use the expander mandrels .

 

[918v]

You over annealed the brass. It is now too soft for reloading and you need to scrap it. Hornady brass is pretty thin so that’s why it got overcooked. How did you decide on the annealing time? You need the brass to be semi hard. I would get a 650 deg Tempilstik and use that as a baseline.

 

[straightshooter1]

These cases were cleaned with SS pins in a rotary tumbler for 45min, surfactant and citric acid added as well. I do agree though, there is carbon still on the ID of the neck. Maybe a SS or Nylon brush would be worth wile to do. I haven't heard much of people specifically cleaning the necks, suggestions?

I would think 45 min is plenty of time to clean the cases after annealing and with the use of SS pins, I'd thing the inside of the neck would be much cleaner "post annealing". In fact, if you want to retain some carbon on the inside of the neck, simply wet tumble without the SS pins. If you were to use hot water along with your surfactant and citric acid, it can take less than 30 minutes of tumbling and the outside should cleaning up nicely and doing so after annealing makes it better for your sizing dies, otherwise that oxidation layer acts like sandpaper on the inside of your die. Just be aware that the wet tumbling tends to peen the mouth edge, curling it inward where you either trim the case afterwards or do a little chamfering afterwards.

 

[n2ishun]

Just a little ritual I do when lubing cases prior to forming.
I use a pad and roll them with the palm of my hand then tap the neck of the case straight down onto the pad.
It might help if there's any debris inside the case and it also lubes the inside and outside of the neck just a smidge.
It might seem simplistic to some of you, but some others still need to hear it.
Figure out some sort of ritual like that and stick with it so you know for a fact that the neck was lubed enough before you shoved it up into the die (I like that it almost sounds sexual).
I've formed necks to larger and smaller size and have honestly (knock on wood) never collapsed a case yet, and I started reloading in the early 80's.

 

[Allthewatts]

I would think 45 min is plenty of time to clean the cases after annealing and with the use of SS pins, I'd thing the inside of the neck would be much cleaner "post annealing". In fact, if you want to retain some carbon on the inside of the neck, simply wet tumble without the SS pins. If you were to use hot water along with your surfactant and citric acid, it can take less than 30 minutes of tumbling and the outside should cleaning up nicely and doing so after annealing makes it better for your sizing dies, otherwise that oxidation layer acts like sandpaper on the inside of your die. Just be aware that the wet tumbling tends to peen the mouth edge, curling it inward where you either trim the case afterwards or do a little chamfering afterwards.

I like the re-ordering on when I would clean. I'll work on implementing that. looking at a few more cases, these ones look particularly dirty in the inside. I think it may be the case that the tumbler was overfilled, leading to poor pin distribution to all of the cases. I'll likely experiment a bit to ensure I do actually get the case necks clean.

I also do chamfer ID and OD edges of the cases post wet tumbling.

You over annealed the brass. It is now too soft for reloading and you need to scrap it. Hornady brass is pretty thin so that’s why it got overcooked. How did you decide on the annealing time? You need the brass to be semi hard. I would get a 650 deg Tempilstik and use that as a baseline.

I anneal to a target hardness level on the case necks. It is possible that I have brought the brass to a softer condition further down the axial length from the shoulder than necessary. I don't see this as an actual issue other than in this instance due to what is likely poor IML cleaning. As for the safety aspect, the case head is full hardness post this annealing schedule (time, power and position).

I did size and form 48 other cases without any issue, so that gives me a bit of pause on how I ensure consistency. These while not my highest precision (the only component swap is brass brand), are still desired to be precision loads.

---

This thread of advice in only a few hours time in the wee hours of the night is awesome. I love the raw feedback when someone can look at some photos and say, nope, your too dirty in x position. It's truly great.

My take always thus far:

1. Verify annealing position, is the hardness in the case shoulder too low. (section a case and verify hardness on axial length)
2. double check mandrel holder position, re-measure clearance to sholder.
3. Run a few cleaning tests, clearly cases are not as clean as desired.
4. Clean post anneal, graphite lube inside diameter of neck before mandrel expanding, and see if problem persists.

 

[KnowNothing256]

Hmm “clearance to shoulder?” The mandrel body die doesn’t index on or even touch the shoulder, but maybe I’m misunderstanding that statement. The only part of the mandrel die that touches anything should be the mandrel itself; no contact between case and body die or die and shell holder.

 

[Allthewatts]

Hmm “clearance to shoulder?” The mandrel body die doesn’t index on or even touch the shoulder, but maybe I’m misunderstanding that statement. The only part of the mandrel die that touches anything should be the mandrel itself; no contact between case and body die or die and shell holder.

The case neck leading edge to the shoulder or step in the mandrel die. As in if that is touching, you'll have super high contact loads unnecessarily.

 

[Feniks Technologies]

I’m assuming this is a non bushing die.

If so, this happens when sizing neck down more than a couple thousandths and then not having enough lube for mandrel.

Either:

- use a bushing die and minimally size the neck smaller than mandrel

- more lube

- use two mandrels and incrementally step the neck

It is *likely* not an annealing issue. Have seen this with cases that were not annealed after several firings.

 

[padom]

All this dirty neck didn't clean causing the issue is crazy. Carbon in the necks is good.

What @Feniks Technologies. Said is where I'm at....you're squeezing the necks down WAY too much then trying to open them back up with the mandrel...

Forster FL sizing dies, un-honed squeeze the necks down wayyyy to much. They are built this way to ensure they properly size ALL brands of brass that vary in neck thickness. This is the exact reason many of use had our Forster dies honed over the years...

This is very easy to investigate on your own....measure the neck OD of a fired case before you size it and write that number down.... now size that case in your Forster die without the expander button....measure the neck again and write thst number down...now subtract the 2 numbers above and you'll have how much your excessively squeezing that neck down... now mandrel that brass and write thst number down....now you can see how much you are opening the neck back up (excessively)... now seat a bullet in thst case and measure the neck for our loaded neck diameter...


I only size my necks down 0.004 under loaded neck diameter then open them back up with a mandrel 0.002.....this leaves a final neck tension of 0.002......

Your only options here are to

1) put your expander back in your Forster FL die and discontinue using that mandrel (there is nothing wrong with this I used Forster FL dies for many years)

2) have your Forster die honed to only squeeze the necks down 0.004 under load neck diameter (careful we have different honed dies for different brands of brass in same caliber due to different neck thickness. You hone to size specific brass like say Hornady or Lapua... bit will not be the same if you use various headstamp brass)

3) get a FL bushing sizing die and use a bushing to squeeze necks down 0.004 under loaded if you want to keep using your mandrel

 

[Haney]

If you clean the necks post annealing and use more lube your problem will most likely go away . From the pic you can see they are dirty enough to not let the mandrel make full contact . With that much carbon in the neck you are reducing the neck ID .

 

[Barelstroker]

When looking at the picture, I notice the mouth of each case seems to be curled in lip & it doesn't appear that any of the case mouths has been chamfered.
It's best to chamfer the case necks before the expander mandrel if you SS tumble or trim the cases.

 

[918v]

A

I like the re-ordering on when I would clean. I'll work on implementing that. looking at a few more cases, these ones look particularly dirty in the inside. I think it may be the case that the tumbler was overfilled, leading to poor pin distribution to all of the cases. I'll likely experiment a bit to ensure I do actually get the case necks clean.

I also do chamfer ID and OD edges of the cases post wet tumbling.



I anneal to a target hardness level on the case necks. It is possible that I have brought the brass to a softer condition further down the axial length from the shoulder than necessary. I don't see this as an actual issue other than in this instance due to what is likely poor IML cleaning. As for the safety aspect, the case head is full hardness post this annealing schedule (time, power and position).

I did size and form 48 other cases without any issue, so that gives me a bit of pause on how I ensure consistency. These while not my highest precision (the only component swap is brass brand), are still desired to be precision loads.

---

This thread of advice in only a few hours time in the wee hours of the night is awesome. I love the raw feedback when someone can look at some photos and say, nope, your too dirty in x position. It's truly great.

My take always thus far:

1. Verify annealing position, is the hardness in the case shoulder too low. (section a case and verify hardness on axial length)
2. double check mandrel holder position, re-measure clearance to sholder.
3. Run a few cleaning tests, clearly cases are not as clean as desired.
4. Clean post anneal, graphite lube inside diameter of neck before mandrel expanding, and see if problem persists.

How did you establish hardness?

 

[Allthewatts]

A


How did you establish hardness?

With the use of a custom modified Webster hardness tester. 3x measurement at each axial station.

 

[918v]

With the use of a custom modified Webster hardness tester. 3x measurement at each axial station.

And to what hardness did you anneal?

 

[2aBaC̶a̶]

sounds like what @padom said, youre sizing too much in one step.

in addition you can chuck your sizing die expander in a drill and hit it with some sand paper to hone it down so that it pre expands the neck slightly before the mandrel. usually how I run mine anyways to straighten dented case mouths.

ive over annealed cases and never crushed them like that. it can effect headspace though.

 

[Average guy]

sounds like what @padom said, youre sizing too much in one step.

in addition you can chuck your sizing die expander in a drill and hit it with some sand paper to hone it down so that it pre expands the neck slightly before the mandrel. usually how I run mine anyways to straighten dented case mouths.

ive over annealed cases and never crushed them like that. it can effect headspace though.

That’s exactly what I have done. Works good

 

[918v]

I have a Lee FL die that sizes the neck to .285” and my RCBS dies size the necks to .282”. My honed Forster sizes down to .288”. I use that one when I don’t anneal.

I use a .263” carbide expander mandrel, and dry lube the necks with graphite, and have no issues ever.

If you use the recommended settings on an AMP machine you pretty much have to size the necks that much and then expand them back out to get a decent grip on the bullet.

 

[padom]

My Forster FL sizing die pre-honed was sizing necks down 0.014 under loaded neck diameter...thats a LOT.

Post up your measurements as i requested in my last post and we can better help you

 

[Gohring65]

Couple things crossing my mind.
First, your brass looks like WW2 surplus brass, it looks over annealed. I have crushed brass like that by purposely over annealing brass and testing it in the die.
If it’s not over annealed, then graphite neck lube would definitely help. And like someone posted about abandoning the mandrel and going with the forester die, it can be set up with the expander up near the neck area giving you excellent run out and mandrel type results.
Honestly though, that brass looks like it’s been very hot. Could just be the pic I guess.

 

[Allthewatts]

And to what hardness did you anneal?

In the center of the 6.5CM Neck (1.773 inches from base on my brass): 61 Rockwell HRB, which is about ~108 HV.

 

[918v]

Maybe your hardness tester is not working right? Have you tested the brass using other means? To what diameter does your die size the neck?

 

[Barelstroker]

I don't think it's really worth worrying about.
I anneal my brass to 100% recrystallization then FLS with the expander ball removed then I use expander mandrels of 0.248" & 0.3045" for 243 Win & 308 Win respectively. I've had 2 collapsed cases out of hundreds sized this way.
The two which collapsed were due to me forgetting to use lube in the case mouth prior to mandrel sizing.
It's not possible to anneal the case necks to much below 80 - 85 HV because regardless of the high temps used, the time required for full annealing down to 65HV is many hours at 700C.
Annealing to 100% recrystallization is kind of self regulating in that the final hardness is mostly dependent on the brass stress prior to annealing. If the brass is annealed between every firing it does not or cannot become very hard & stressed so the annealing cycle has relatively small changes in hardness.
This is why AMP recommend annealing between every firing because the brass hardness will reach an equilibrium state whereby the hardness fluctuates a small amount between annealed & fired.

 

[357Max]

In the center of the 6.5CM Neck (1.773 inches from base on my brass): 61 Rockwell HRB, which is about ~108 HV.

Did you figure out your annealing time via the Webster on clean brass, as in no carbon?

If so the same setting + carbon coated interior will put a lot more heat into it.

What do the 3 cases in OP measure on the Webster?

 

[Allthewatts]

Determined annealing time for this lot of brass after cleaning. In the same state other brass would be annealed. Its just Hornady brass right now, so I wasn't too worried about the loss of a case.

I haven't measured the buckled cases, I was going to section and etch the brass to look at the grain structure and see if anything jumps out.

But great idea! I have a few measurements to make per recommendations above.

 

[Allthewatts]

I took a look at a few of the lots of fired, and cleaned brass, and all the inside of the necks look much cleaner. Though after mandrel expansion, some streaking is seen. So it may actually not be a cleanliness issue.

I did however lubricate the mandrel a bit, and then every 5 rounds, re-lubricated the mandrel with a thin invisible layer of case lube. No crushed cases. In fact, very easy to expand.

Case neck measurements per recommended above:

Fired case:	⌀ .2940 in
Sized case neck:	⌀ .2825 in	Δ -0.0115 in
Expanded case neck:	⌀ .2900 in	Δ +0.0075 in
Seated case neck:	⌀ .2925 in	Δ +0.0025 in

My take away from these averages of a sample of 5x cases appears to indicate that there is an unnecessary amount of forming of the neck during the sizing process. As such, honing the FL sizer die to something closer to ⌀ .286 would reduce the unnecessary "necking down, or OD trimming the brass more, which adds another variable!

 

[Islas82]

Same thing happened to me while using Hornady brass, has never happened with lapua or Peterson even if I run the mandrel dry. My advice is if you’re using Hornady brass make sure you lube up the mandrel or your necks to reduce friction, that’s what’s causing it.

 

[padom]

I took a look at a few of the lots of fired, and cleaned brass, and all the inside of the necks look much cleaner. Though after mandrel expansion, some streaking is seen. So it may actually not be a cleanliness issue.

I did however lubricate the mandrel a bit, and then every 5 rounds, re-lubricated the mandrel with a thin invisible layer of case lube. No crushed cases. In fact, very easy to expand.

Case neck measurements per recommended above:

Fired case:	⌀ .2940 in
Sized case neck:	⌀ .2825 in	Δ -0.0115 in
Expanded case neck:	⌀ .2900 in	Δ +0.0075 in
Seated case neck:	⌀ .2925 in	Δ +0.0025 in

My take away from these averages of a sample of 5x cases appears to indicate that there is an unnecessary amount of forming of the neck during the sizing process. As such, honing the FL sizer die to something closer to ⌀ .286 would reduce the unnecessary "necking down, or OD trimming the brass more, which adds another variable!

There you have it. Excessively squeezing the necks down to then have to open them back up a ton.

Switch dies or send that die to Forster to be honed foe the brass you are going to use...

 

[918v]

My RCBS dies size the necks to .282” and this just doesn’t happen.

 

[savagemann]

This thread has been helpful. I am starting to process my 6.5cm brass with similar processes and dies etc.

 

[Rhed]

That happened to me before. Ruined 3 cases and figured the expander has too much bite when contacting the case mouth. Good thing I had some Redding Imperial dry case lube. Dip the case in the media.And you don’t even need to re-apply when seating bullets too which is a plus. After awhile, I then switched to carbide expanders.

 

[Allthewatts]

Well, a small update, but I've loaded a lot more rounds, and with less cases in the tumbler at a time, some more careful deburring, and most importantly lubricating lubricating with the Redding Imperial Dry Neck Lube Kit, I haven't had any issues at all. Much lower seating force using this over a wax based lubricate on the mandrel body.

Thanks all!

 

[dnchrist]

These cases were cleaned with SS pins in a rotary tumbler for 45min, surfactant and citric acid added as well. I do agree though, there is carbon still on the ID of the neck. Maybe a SS or Nylon brush would be worth wile to do. I haven't heard much of people specifically cleaning the necks, suggestions?

I clean until they are clean.

 

[Barelstroker]

You over annealed the brass. It is now too soft for reloading and you need to scrap it. Hornady brass is pretty thin so that’s why it got overcooked. How did you decide on the annealing time? You need the brass to be semi hard. I would get a 650 deg Tempilstik and use that as a baseline.

Bullshit.

 

[ma smith]

Well, a small update, but I've loaded a lot more rounds, and with less cases in the tumbler at a time, some more careful deburring, and most importantly lubricating lubricating with the Redding Imperial Dry Neck Lube Kit, I haven't had any issues at all. Much lower seating force using this over a wax based lubricate on the mandrel body.

Thanks all!

Seems like this thread is old and has been settled long ago...

 

[Allthewatts]

I clean until they are clean.

Helpful, thanks.

 

[r.tenorio671]

..I have had that happen a couple of times when seating bullets in virgin Starline 6.5G brass I converted for 6ARC. I use the Hornady 2 die set (FL) with the micro adjuster on the seating die. My brass was annealed straight from bag, resized, trimmed, wet tumbled, dried & chamfered then loaded up days later. For the cases that buckled, a slight increase in resistance was found, but by time that happened, the case was already buckled. I attributed it to friction due case neck inside being so dry. My fix; ... slight swipe of Imperial wax on forefinger & thumb, roll bullet base between thumb & forefinger, seat.

...and before ppl pop on and dissect my comments/process...no, the die is not too far down and case mouth contacting the internal step; no, my expander button is not too small, calipered and measured to correct size. While trying to determine the cause, some of the loaded rounds that had increased resistance during the seating, BUT DID NOT BUCKLE, I could discern that there appeared to be a very, very slight bulging at the shoulder & case body junction. I was able to confirm this by checking these loaded rounds in my Sheridan slotted gauge. They would not drop fully into the case, unlike they did when checking after converting to 6ARC. They hung up and a very slight "shine" was seen circling the casing at that junction. I would use those rounds to warm the barrel up or sighters as they would chamber under the force of the BCG releasing from the locked back condition. I use concocted lanolin/alcohol for my lube in a sprayer so my case mouths get lubed as well so the expander doesn't "seize" during the process. I also apply some lube to the expander with a Q-tip every so often when sizing cases. During loading/seating, I keep the tin of Imperial handy just in case. I doubt the miniscule amount of Imperial I might use will have any effect on the powder. I am not so OCD'ed about the potential effect on bullet release, especially as the loaded rounds can sit for a week or more after loading before I can get out and shoot them..

YMMV

 

[dnchrist]

..I have had that happen a couple of times when seating bullets in virgin Starline 6.5G brass I converted for 6ARC. I use the Hornady 2 die set (FL) with the micro adjuster on the seating die. My brass was annealed straight from bag, resized, trimmed, wet tumbled, dried & chamfered then loaded up days later. For the cases that buckled, a slight increase in resistance was found, but by time that happened, the case was already buckled. I attributed it to friction due case neck inside being so dry. My fix; ... slight swipe of Imperial wax on forefinger & thumb, roll bullet base between thumb & forefinger, seat.

...and before ppl pop on and dissect my comments/process...no, the die is not too far down and case mouth contacting the internal step; no, my expander button is not too small, calipered and measured to correct size. While trying to determine the cause, some of the loaded rounds that had increased resistance during the seating, BUT DID NOT BUCKLE, I could discern that there appeared to be a very, very slight bulging at the shoulder & case body junction. I was able to confirm this by checking these loaded rounds in my Sheridan slotted gauge. They would not drop fully into the case, unlike they did when checking after converting to 6ARC. They hung up and a very slight "shine" was seen circling the casing at that junction. I would use those rounds to warm the barrel up or sighters as they would chamber under the force of the BCG releasing from the locked back condition. I use concocted lanolin/alcohol for my lube in a sprayer so my case mouths get lubed as well so the expander doesn't "seize" during the process. I also apply some lube to the expander with a Q-tip every so often when sizing cases. During loading/seating, I keep the tin of Imperial handy just in case. I doubt the miniscule amount of Imperial I might use will have any effect on the powder. I am not so OCD'ed about the potential effect on bullet release, especially as the loaded rounds can sit for a week or more after loading before I can get out and shoot them..

YMMV

 

[dnchrist]

I don't know if it will help, but on the calibers that I had cases/shoulders crushing, I disabled the crimper and crimped with a Lee Factory Crimping Die. That removed the very strict necessity for exact same case length every time. Sometimes I find the need to roll the projectile in a very light lube before inserting.

 

[918v]

Bullshit.

No it isn’t.