Freaked out now - Case head seperation.

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mungojeerie

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I will start by saying that I am new to reloading and I admit that despite triple checking everything along the way I still managed to fudge up which has reinforced with me how important it is to be very clear on what your doing when your doing it, that being said my mistake should not have resulted in my experience.

For my first reloads I reloaded for .270 wsm, 6.5 creedmoor & .338 win mag. each of which were loaded on different days, so there was no chance of powder mixup between calibers. The .270wsm I loaded 4 different bullets each with two different types of powder using brass that has been used many times, but for which I am unsure of how many times. The brass was annealed, trimmed, deburred and chamfered. The 6.5 creedmoor I loaded one type of bullet with two different powders using brand new brass that was deburred and chamfered. All of these round performed as expected and without concern of any known issue. The .338 was another issue.

I originally loaded 12 rounds with 250gr Berger Classic Hunters, found that the seating depth required to accommodate my magazine was too great, so unloaded them using a Lyman bullet puller hammer and reloaded them using 225gr Hornady SST.
This was my process:
Brass used: once fired (by me) factory Hornady 225gr SST rounds
Primers: Federal large rifle
Powder: IMR 4831
Bullets: 225gr Hornady SST
Rifle: Tikka T3 lite stainless.

I took the once fired factory brass, de-primed it, cleaned it in the tumbler, blew it all out and off with compressed air, annealed it, lubed and resized them using Hornady Dies, cleaned it in the ultrasonic cleaner, dried it in the dehydrator, trimmed it (next time I will do this step before cleaning) deburred it, chamfered it, resized and cleaned the primer pocket (probably didnt need the resizing), primed it, then loaded powder and seated bullets, no crimping.

My big mistake was I had looked at a number of sources for suggested powder, the lyman book, the rcbs book, online, hornadys website etc. I had planned on using IMR 4831, but when I went to do it I went off of hornadys website, My mistake was loading IMR 4831, when Hornadys site suggests H 4831 (Yes, I know that different brands of powder with the same number are not usually interchangeable). Hornadys suggested load was 60.9min - 73.5max, I loaded to 61gr, .1gr over suggested min, but 12.5gr less than max, figured should be good. so I loaded 61gr of IMR 4831. Seated my bullet .0200 off of the lands which gave me a COAL of 3.3300, Hornadys listed Coal was 3.3200.

My first shot at the range felt fine, I neglected to carefully inspect the cartridge, had I done so I would have noticed that the primer had unseated and was now no longer lower than the case head. could have been due to over pressure, could have been due to the likely unnecessary primer pocket resizing. no other signs of pressure were noticed, no case bulging, the case ejected effortlessly etc. My second shot also felt fine but when I ejected the round with my left hand ready to catch the cartridge, the bolt disengaged fine but the shell didnt jump put, I figured it was just sitting on top of the magazine, so I ejected the mag expecting the case to drop, but instead just the separated case head came out. I was instantly freaked out, I raised the gun and the remainder of the shell easily slid out of the chamber with nothing but gravity.
I stopped shooting that gun and finished my evening with the .270 and 6.5

When I got home and started going over things is when I caught the powder mixup. I dont even own H 4831 so there is no way that I put that in there, 100% it was IMR 4831, so right away I thought shoot, that is my problem, however when I looked up Lymans and RCBSs Min loads for IMR 4831 they were 65gr and 67gr respectively, a fair bit higher than the 61gr I loaded so they should be under powered. Did I load the wrong measurement? Nope, was sure I didnt, but just to check I popped a cpl rounds open with the bullet pulling hammer and remeasured, just under 61gr now (Im assuming there was some loss in bullet pulling, emptying, cleaning etc)

So now Im stuck with what to do. Im afraid to shoot those rounds and dont know what to change. could it be the brass? Someone told me you shouldnt shoot factory round brass because its not meant to be reloaded. how can that be? I have and would never do it, but I know lots of ppl that pick up random range brass to reload, most if not off all of which would be factory rounds.

Below I will include photos of the reloaded round on the left, the factory round on the right. the first shot with the un-seated primer and then the second shot with the case head seperation. Any suggestions or thoughts are greatly appreciated. what would you try next? and what would you do with the current loaded rounds?

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Case head separations come almost entirely from sizing the case too much.[pushing the shoulder back more than is necessary for your rifle]
A backed out primer is usually a low pressure load with a bit of excess headspace [again, oversizing the brass].

I would get rid of that multi-fired brass and start fresh. Factory loads fired to acquire brass is just fine.....don't listen to that naysayer.
You need to read up on how to FL size your brass to fit YOUR rifle's chamber. If you push the shoulder back any more than .002", you are
asking for case separations after very few reloads. My personal max is .001" Don't be afraid to ask questions....learning is a process. Regards, EE
 
Dave (EE) gave you the right answer, as usual. There are plenty of youtube videos about this topic. You can have one of those Hornady tools that measure case base to shoulder and work accordingly to bump the shoulder back 0.002. An alternative it to keep bumping the shoulder until your case fits with pressure applied on the bolt on the last quarter of its movement when you close it. This is called crush fit. The goal is to avoid excessive headspace and from there case head separation. Erik Cortina has a good video about the first method and the Real Gunsmith also a good one about the second method. Learn as much as you can and do not leave any chance to luck.
 
i always check the inside of the casing.
I use a paper clip that i bent and sharpened.
You put it inside the fired case.
and slide it up and down.
If you feel some resistance, I SCRAP THE CASE
SAVES ME A LOTS OF TROUBLE
OLD TIMER LOU
 
That .338 load was way too hot..the primer is flattened badly. Second, case don’t last forever. As mentioned here, oversizing is one of the cause, headspace another, but in reality, each time a cartridge is fired, brass flow forward. Hot load shorthen brass life.
If you get 4-5 reload out of a case in your caliber (.270 maybe a little more), that should be it and case be tossed.
 
Eagleye said:
Case head separations come almost entirely from sizing the case too much.[pushing the shoulder back more than is necessary for your rifle]
A backed out primer is usually a low pressure load with a bit of excess headspace [again, oversizing the brass].

I would get rid of that multi-fired brass and start fresh. Factory loads fired to acquire brass is just fine.....don't listen to that naysayer.
You need to read up on how to FL size your brass to fit YOUR rifle's chamber. If you push the shoulder back any more than .002", you are
asking for case separations after very few reloads. My personal max is .001" Don't be afraid to ask questions....learning is a process. Regards, EE
Click to expand...

OP, this is the best advice your likely to get.

You can check the inside of the case until you're blue in the face and all it will tell you is that the case stretched the first time it was fired.

After that, it's pretty hard to detect much difference.

Eagleye is telling you exactly how to avoid the situation from happening again and his instructions are easy to follow.
 
Case separations like that are usually caused by excess headspace. The firing pin impact drives the case forward, primer fires, is pushed back against the bolt face, case expands against the chamber walls, case head is pushed back, reseating and flattening the primer and stretching the case wall exactly where yours failed.
Not caused by a hot load.
If you were to section the heads of some fired cases you might find the internal ring of incipient separation. You might also find it with a paper clip probe as suggested above.
You cannot trust this batch of cases. They my not be trustworthy for use in your rifle.
Get new ones.
As described above, for sizing purposes, treat the cases as if they were rimless, and size to suit your rifle. Belted cases are known for short case life unless reloaded as if rimless.
 
pics 3 and 5 show an extremely flattened primer, meaning extremely high pressure. just backing up what janeau has already posted. check your powder scale for accuracy and uniformity.
 
barsik said:
pics 3 and 5 show an extremely flattened primer, meaning extremely high pressure. just backing up what janeau has already posted. check your powder scale for accuracy and uniformity.
Click to expand...

Not necessarily. Look at the photos of the primers standing proud. If the case stretches and the head moves back to the bolt face, the primers will be flattened.
 
A. Stated to be once fired brass, not old tired cases.
B. The round that was fired first backed the primer out but did not rupture the brass. To have that primer sticking out that far would require excess headspace as conventionally measured to the front of the belt.
Both primers are flattened, not unusual in a high pressure round like the .338 Win Mag.
No sign of ejector imprint on the case head? A well known overpressure sign with some rifle designs.
No sign of primer cratering, which would be a sure indicator of questionably high pressures.
This is a massive stretch for a first time reload, indicating huge excess headspace or oversize chamber.
Was this brass originally fired in this rifle? Because belted cases headspace on the belt, not the shoulder, if the original gun that fired these cases had an oversize
( too long ) chamber the cases would expand forward to fill the chamber on initial firing. Possible but not likely in a factory rifle, but a distinct possibility if the rifle had been rebarrelled or rechambered. An out of spec sizing die would be nearly impossible. Due to a lack of proof laws in this country anyone can chamber a barrel, screw it into an action and send it on to a new owner with no standard testing or controls. A rifle in a belted cartridge with an over length chamber will probably perform just fine with factory ammo and may go through several owners before trouble shows up when someone starts reloading for it.
To me the prime suspect here is the dimensions of the rifle chamber.
 
I vote for oversized - over pressure load , used- done caee that should not have been reloaded.
Keeping track of number of firing - internal inspection with wire or better with borescope will have catch it before loading it.
The real culprit here..is trying to extend case life..when it is done- it’s done.
 
Belted cases headspace using the belt. The headspace gauges are short and only involve the recess reamed for the belt. The chamber could be half an inch too long and the gauges will not detect it. Or, the chamber could be short and once again the gauges will not show it.
A belted magnum reamer cuts both body and belt recess, in a single operation.
If the headspace is within limits, the case will fireform to the chamber. This expansion may or may not be excessive. If the case is fully FL sized, with the shell holder contacting the die, the case body will be sized as far as possible. Perhaps way more than necessary. This can contribute to separations.
In addition, the thickness of the belts can vary. If belts are on the thin side, or if the rim recess is maximum, and cases are sized to the limit, the possibility of separations in increased.
Resizing the case as if rimless avoids complications.
 
My first advice to the OP is to take a breath and calm down. This was not a major mishap; you didn't almost die. Some people confuse case head separations and case head failures, and think they are equally serious. They are not. Head separations are almost completely benign. I actually have a rifle that probably over 90% of the cases that fail in this rifle fail by separating. I happily shoot it knowing this (though don't get me wrong, I would like to solve the problem, as brass life is much shorter than I get in other rifles).

The most serious thing I see in your post is one that actually is not a factor in this, and that is reading the powder data wrong. In your case it actually resulted in a milder load, but it could just as easily gone the other way. You need to figure out why you didn't catch that, and make sure it doesn't happen again.

Otherwise, the head separation and the primer setback both hint at badly excessive headspace. You should figure out if that is from your sizing practice, or a problem with the dies, or the rifle chamber. And if you can, fix it. Or resign yourself to very short case life.

And yes, the idea that cases that originate with factory ammo are not intended to be reloaded is complete nonsense. There was almost certainly nothing wrong with your brass.
 
I never fully resize anything except a pump action.
The paperclip test is kinda ok, but any new to me rifle after shooting 2 and 3 time reloads I cut a brass in half.
Any one doing full resizing should always check case stretch, checking the shoulder length before and after is good to but sacrificing a round to the hacksaw is the really the best test.
 
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This website might provide some useful info on belted magnum headspace and resizing: https://www.larrywillis.com/

He has an article in this website about cause and effect RE belted cartridge case head separation: https://www.larrywillis.com/headspace.html

I don't shoot/reload any bottleneck belted magnum cartridges, so correct me if I am wrong: What I understand is:

- The rifle manufacturer/gunsmith sets the headspace, bolt face to belt against the chamber.

- For some reason (not understood by me), some belted magnum chambers are cut quite long, sometimes e.g. 0.020" longer than the shoulder of the case. Therefore the first firing of the case can cause it to stretch alot, possibly weakening the case in the typical area above the web.

- The reloader should resize the fired case for that specific rifle, just like it was a non-belted rimless case, minimizing shoulder setback, (no more than 0.001 to 0.002, or just neck size), to prevent excessive case stretching. The reloader needs a headspace comparator tool, used the same way as for bottleneck rimless, beltless cartridges.

- Hornady lists their headspace comparator tool bushing size 0.420, part#E420 for belted magnums.
 
Unless you adjust your sizing die to headspace on the shoulder and not the belt you will certainly continue to have case head seperations and very short case life. Eagleye nailed it.
 
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