Don Fischer
New member
Did you ever figure out what it is?
Case head separation
- Thread starter Stats Shooter
- Start date
And then? There is the generous chamber, I was asked to make a 'shop call', a builder of bench rest type rifles said he had a problem with a rifle he built. Seems the owner/shooter had a problem with the fired cases; I asked the builder about the accuracy, he said there was no problem with accuracy. I suggested to the builder the owner/shooter was an Internet reloader. And then, I informed the builder I could 'fix' the problem.
F. Guffey
JeepHammer
Moderator
Mr. Guffy (and others) are correct, a properly sized brass for YOUR chamber will stop a bunch of issues & problems.
Mississippi has previously written about fitting his brass to his chamber, and he's shooting really accurately...
What I read was this was a totally unexpected fluke and was wondering if it was an anomaly or some issue that just cropped up...
I choose to make the Chambers fit properly sized SAAMI ammunition so much ammo will fit about any chamber.
All things being equal, and his brass NOT being stretched by an oversized chamber, a press 'Hesitation' ring seemed a likely culprit.
You can not find, or predict a hesitation ring in brass.
There are no visible indicators, and the separation will happen in brand new brass (hense the military issuing separated case removing tools).
My very first try at new brass produced these hesitation rings, some would separate on first or second firing most times, well before case stretch came into play.
If it hadn't been for that experience, and a friendly brass engineer at Federal I wouldn't have known about it and probably wouldn't have continued manufacturing brass.
The problem had plagued me for nearly a year when I mentioned it to the brass engineer and he knew instantly what the problem was, and was kind enough to share what he knew.
(Eternal thanks Frank!)
Said they have the same issue every time they set up a new press getting the hydraulic bypass system calibrated, and went on to tell me the reason for hydraulic presses was old flywheel pin presses (what I was using) was almost impossible to keep tight enough to stop hesitation rings.
Mississippi has previously written about fitting his brass to his chamber, and he's shooting really accurately...
What I read was this was a totally unexpected fluke and was wondering if it was an anomaly or some issue that just cropped up...
I choose to make the Chambers fit properly sized SAAMI ammunition so much ammo will fit about any chamber.
All things being equal, and his brass NOT being stretched by an oversized chamber, a press 'Hesitation' ring seemed a likely culprit.
You can not find, or predict a hesitation ring in brass.
There are no visible indicators, and the separation will happen in brand new brass (hense the military issuing separated case removing tools).
My very first try at new brass produced these hesitation rings, some would separate on first or second firing most times, well before case stretch came into play.
If it hadn't been for that experience, and a friendly brass engineer at Federal I wouldn't have known about it and probably wouldn't have continued manufacturing brass.
The problem had plagued me for nearly a year when I mentioned it to the brass engineer and he knew instantly what the problem was, and was kind enough to share what he knew.
(Eternal thanks Frank!)
Said they have the same issue every time they set up a new press getting the hydraulic bypass system calibrated, and went on to tell me the reason for hydraulic presses was old flywheel pin presses (what I was using) was almost impossible to keep tight enough to stop hesitation rings.
Stats Shooter
New member
I guess i will repeat it....I typically use 0.0025" shoulder clearance for bolt action rifles and 0.004" for my gas guns. Guffy usually has some good info if you can get past the pretentious anecdotes and condescending pronouns used for us poor ignorant hacks.
Anyway, I think I have seen enough information posted by Nick and jeephammer to conclude that this is just something that can happen. There may have been a sign that this case was about to fail, but the so far, out of the hundreds I have checked in the last few days, I have found no indication or warning signs.
I realize when a question is posed on a forum, you will get a bunch of common mistake suggestions. That's certainly not a problem since folks aren't aware of what you are doing, your knowledge or skill, your rifle etc,...So those are appreciated also.
One really good suggestion is MG suggesting I don't buy capped, sized, and cleaned once fired brass.... That could certainly help identify a case that needs culled.
Second/2 time fired? After that the story went something like the cases were sized etc.. Just an opinion but when I tell stories like that I start with "Once upon a time" or "you are not going to believe this" or "me and my buddy were surrounded and outnumbered" or "now listen up men" or "now hear this" and then there is the Air Force story and we never want to forget the Marines.
Again, I purchase cases that will not chamber in one of my rifles because manufacturers do not sell cases for long chambers. When I purchases once fired cases I purchase the cases with the original primer, if the primer has been removed I do not assume it is a once fired case. But, if the case has been fired once the case head expansion shoulder be .00025", if the case has been hammered and or fired more than once the case head should be larger in diameter than a factory once fired case.
And then? There is that cute little saying about the firing pin striking the primer and then driving the whole she-bang including the case, powder and bullet to the front of the chamber
I have one chamber that has .016" clearance between the shoulder of the chamber and shoulder of the case; and the firing pin in that rifle is a killer, it crushes the primer before the case, powder and bullet know their little buddy (the primer) has been crushed. After all of that there is that silly story about the firing pin driving all of that weight forward 
F. Guffey
m&p45acp10+1
New member
I have had two ICHS happen. Both with factory ammo that was new. Both in semi auto rifles. One was an M1 Carbine. One was an AR15. The M1 required using cerosafe alloy to remove. The AR only required the use of a chamber cleaning brush.
I can say that I have seen some that had been fired from a fluted chamber look like that. I know that if I see someone shooting a Sig Sauer rifle to be sure not not use their brass. The fluted chamber in them ruins brass in one firing.
I can say that I have seen some that had been fired from a fluted chamber look like that. I know that if I see someone shooting a Sig Sauer rifle to be sure not not use their brass. The fluted chamber in them ruins brass in one firing.
Stats Shooter
New member
This is really the lesson here. Sure the seller probably assumes each case is once fired. It is likely that most cases are indeed once fired...But there is the chance that one or more are not once fired. And that might be what I have experienced.
So the lesson I'm taking from this is: When buying once fired brass, buy it unprocessed so that someone with a small based die or similar can't hide the fact it was fired by a rifle with a big chamber or some unsupported chambered machine gun.
I have had repeated separations and like my brother, I could find no rings you can feel with a pick or paper clip in the brass, even on the other side of the case where it had not cracked yet.
There seems to be more than one mechanism involved.
I won't claim to know what it is, possibly a combinations of the two.
There seems to be more than one mechanism involved.
I won't claim to know what it is, possibly a combinations of the two.
supercub99
New member
Been there done that. Noticed it in bolt action military 03's. No clue and as RC said, couldn't detect a line yet had a few show up on the next firing. In my case the solution was running two FL sizing's dies, one for 2 guns and one for all the others (4). If I recall, one die was 2.04 and the other 2.05. I also went to PPU and RP brass and ditched that batch of Win. Haven't had one since. I can say when I saw one, others followed a cycle or two later.
Most were mil chambers, one was a custom build I did. I have one of the Lyman bore scopes now and check from time to time some of the brass with over 15 cycles. Works great for that although I haven't found any issues so far. I also now wet ss tumble so the brass is shiny clean inside and probably much easier to see if one shows up. Cut a case open sometime, one that has been dry tumbled and you'd be surprised how coated it is inside.
I can only speak from the bolt gun side, the gas guns are as mentioned, can have different issues.
Most were mil chambers, one was a custom build I did. I have one of the Lyman bore scopes now and check from time to time some of the brass with over 15 cycles. Works great for that although I haven't found any issues so far. I also now wet ss tumble so the brass is shiny clean inside and probably much easier to see if one shows up. Cut a case open sometime, one that has been dry tumbled and you'd be surprised how coated it is inside.
I can only speak from the bolt gun side, the gas guns are as mentioned, can have different issues.
A few years back I had one Hornady .204 case separate just at the bottom of the neck. The case was on it's 2nd firing, had never been annealed and was not a hot load. I did not even realize that there was a problem until I was replacing the case back into the box and realized the neck was missing. A cleaning rod with a dry patch and it popped it right out.
I am still loading cases from that batch after 12 firings and 2 "annealings" and have never had any more issues. Sometimes things just happen. I am sure there was some internal flaw in that case but what it was will never be determined.
I am still loading cases from that batch after 12 firings and 2 "annealings" and have never had any more issues. Sometimes things just happen. I am sure there was some internal flaw in that case but what it was will never be determined.
JeepHammer
Moderator
I can't for the life of me remember what the technical term is for press hesitation,
I think I only heard it once, all other times it was simply called hesitation rings.
Anyway, no outward signs, but the brass is basically two pieces pressed together really hard, the brass (and copper, aluminum, etc) separates when the draw stops & restarts.
Metals act under a completely different set of rules when they go 'Plastic' under pressure forming.
I don't understand then reason why the rings form or why there is such a week bond between the two parts on either side of the hesitation ring, if anyone knows please elaborate.
I've seen it several times, but it was my old press causing it, it's a one in a million with commercial brass since they have been aware of it since the mid 1800s, well known problem with them, but when I stared I had no idea.
Now, consider this,
The military used outdated equipment until very recently, Milbrass often did it more frequently, and the military still issues broken case extractors when they DO NOT reload brass...
By the way, The brass engineer that helped me pointed that out, and since he worked for ATK/Federal I listened.
Personally, before I screwed up manufacture, I think I only saw one or two separated cases in 3 decades...
I think I only heard it once, all other times it was simply called hesitation rings.
Anyway, no outward signs, but the brass is basically two pieces pressed together really hard, the brass (and copper, aluminum, etc) separates when the draw stops & restarts.
Metals act under a completely different set of rules when they go 'Plastic' under pressure forming.
I don't understand then reason why the rings form or why there is such a week bond between the two parts on either side of the hesitation ring, if anyone knows please elaborate.
I've seen it several times, but it was my old press causing it, it's a one in a million with commercial brass since they have been aware of it since the mid 1800s, well known problem with them, but when I stared I had no idea.
Now, consider this,
The military used outdated equipment until very recently, Milbrass often did it more frequently, and the military still issues broken case extractors when they DO NOT reload brass...
By the way, The brass engineer that helped me pointed that out, and since he worked for ATK/Federal I listened.
Personally, before I screwed up manufacture, I think I only saw one or two separated cases in 3 decades...
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JeepHammer
Moderator
Found my shop notes, it's called "Dislocation Density".
Hesitations cause "Twinning", fault lines formed during re-crystallization, "...when atoms shift under great force" is the metallurgical definition.
Pretty good definition of the drawing process.
Hesitations cause "Twinning", fault lines formed during re-crystallization, "...when atoms shift under great force" is the metallurgical definition.
Pretty good definition of the drawing process.
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And then there is the old term that goes something like: "Get a bigger hammer", the scary part of that advise is the part that makes sense to those that are shop skill challenged. I attempted to loan a hammer to someone that thought he needed one. I handed him the hammer and he seemed to be confused so I had to ask what was it that he did not understand about hammers. I did not know if he wanted to destroy something etc. etc.
He wanted to borrow a hammer in 10 words or less.
F. Guffey
Support doesn't have anything to do with a case stretching, length wise. It would be pretty easy to tell if the gun it had been fired from had excessive head space because after sizing you would have had a lot more than normal amount of trimming needed.
When you purchase "once fired" brass you should just think "at least once fired". If you are buying it already sized and trimmed you are not going to get any signs that something is wrong with it but where there is one bad apple, others are near by.
On the concentricity gauge I built I added an arm with a bearing in the tip that lines up with the dial indicator.
It allows me to non destructively measure case wall thickness.
Had you shoved your separated case onto it before you loaded it and slowly slid the case towards the mouth, you could have seen the needle start at the thickest point, go low where it was thin where it was stretched and then back up to normal thickness.
You could have scrapped it at that point. If another case started thick and was uniform with the thinnest part being the mouth, it would be ok.
Stats Shooter
New member
jmorris:
That is a pretty neat device, but I don't need it....A dental pick will accomplish the same task. A sharp, hard, dental pick will easily feel a pressure ring. I have culled plenty of cases using the dental pick from range pickup brass.
However, as some have pointed out, there doesn't need to be excessive headspace in some situations for there to be casehead cracking/separation.
Support does matter. Because if it fires slightly out of time/battery the case can bulge at the rear near the head. If it is sized back down, the bulge will be removed, but that spot will still be weak, and when it is squeezed and trimmed before it gets to me, the only way to know is a device like yours or a dental pick.
Furthermore, I have checked over 500 of the other cases by now, and they show no ring...or at least nothing a dental pick can feel. Which means there are no red flags. Sometimes, stuff just happens. If you reload enough, it is likely all of the quirky little failures that are possible will happen to you at some point.
That is a pretty neat device, but I don't need it....A dental pick will accomplish the same task. A sharp, hard, dental pick will easily feel a pressure ring. I have culled plenty of cases using the dental pick from range pickup brass.
However, as some have pointed out, there doesn't need to be excessive headspace in some situations for there to be casehead cracking/separation.
Support does matter. Because if it fires slightly out of time/battery the case can bulge at the rear near the head. If it is sized back down, the bulge will be removed, but that spot will still be weak, and when it is squeezed and trimmed before it gets to me, the only way to know is a device like yours or a dental pick.
Furthermore, I have checked over 500 of the other cases by now, and they show no ring...or at least nothing a dental pick can feel. Which means there are no red flags. Sometimes, stuff just happens. If you reload enough, it is likely all of the quirky little failures that are possible will happen to you at some point.
Nothing like starting all over but some believe the case has head space and somehow they started reloading and missed the first lessons about bump presses and pressed that that do not bump. And I ask: "How can a reloader bump the shoulder back with a die that has case body support? And then there is that answer I am getting more frequently: "It does it because I say it does it and everyone should know what I mean".
F. Guffey
It depends on what it was fired from but if you are talking about lack of support like "generous" SMG chambers, where you have to roll/push through size the brass to remove it, you could tell that because the brass wouldn't case gauge. Because your "full length" sizer can't/doesn't actually size the entire case. So you get something like this.
There are various causes from damaged brass open bolt beltfed 308's like the M240 make it hard to be "out of time" though. The likely source is the barrel, they can only handle sustained fire for about 2 min before they have to be swapped and it's not uncommon to have a barrel in service that is at the end of its life.
FWIW If your waiting on the case to get so bad you can feel the ring from the inside with a paper clip or dental pick, you could be firing cases that are already separating and go "thick, thin, thick" and you just can't tell. Often by the time you can "feel" it from the inside you can see it from the outside.
Yes, it is fundamental. the shell holder has a deck height of .125", I know, it is alleged the manufacture of the shell holder must match the manufacturer of the die and I never understood that. I measure the deck height of the shell holder' if the deck height is .125" that is all it can do. But! If the deck height is not .125" I place the shell holder in the box of high esteem. I purchased a set of Redding Competition shell holders at a gun show, it was a #6 set, I paid $5.00 for it, I thought there had to be something wrong with the set. Sure enough, the #2, 3 and 4 shell holders were off by .001" each.
F. Guffey
F. Guffey
Redding competition shell holders come in sets of five. +.002, +.004, +.006, +.008, +.010 and are marked for how much they will reduce headspace accordingly.
http://www.redding-reloading.com/online-catalog/35-competition-shellholder-sets
You can adjust a die with better precision than .002" for less than a $56 set of shell holders, for one specific case head, with an easy to make fixture and a dial indicator.
http://www.redding-reloading.com/online-catalog/35-competition-shellholder-sets
You can adjust a die with better precision than .002" for less than a $56 set of shell holders, for one specific case head, with an easy to make fixture and a dial indicator.
I found my Garand's headspace correlated with a jiiiust-close case headspace dimension of 2.049" as measured with the Hornady comparator.
Unfortunately, the Redding die set I was using was sizing cases down to 2.036-ish
eek
So now I simply cam-over (ensuring consistency with that "body-supporting" die
) using a 0.010" feeler gauge between the shellholder deck and the die for a final case dimension of 2.047"
(see Guffy? I do listen)
Unfortunately, the Redding die set I was using was sizing cases down to 2.036-ish
eekSo now I simply cam-over (ensuring consistency with that "body-supporting" die
) using a 0.010" feeler gauge between the shellholder deck and the die for a final case dimension of 2.047"(see Guffy? I do listen)