Case head separation gives me food for thought

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Elkins45

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I had a case head failure in my Savage 270 bolt action rifle Monday at the range. The load was 56.0 grains of IMR 4831 behind a Hornady 130 grain spire point. It's the same load I have hunted with for 20 years now. I knew something bad had happened the minute I pulled the trigger because there was smoke everywhere, my face was peppered with powder and I could feel the impact of a jet of gas (and could see a black mark) on my right hand. Fortunately I wasn't hurt in any way, although if I hadn't been wearing glasses I'm pretty confident I would have suffered at least some damage to my vision.

The rifle didn't suffer much damage other than to the extractor, which was blown to the outside of the bolt. It didn't pull the damaged case and I removed the bolt and noticed it had been dislodged. I shoved it back into the correct spot and it seems to be working just fine. It was clear that a LOT of gas had been blasted out of the vent hole on the side of the action from the scorch mark on the stock, the amount of smoke, and the displacement of stuff on the bench next to me. Fortunately I was alone on the line so nobody was next to me to absorb the blast. I'm 99% sure the reason for the case failure was my own stupidity in using an old case one too many times without checking to see if the sidewalls were thinning.

So what's the lesson, you ask? Well, it's this: notice how I described the burn on my RIGHT hand? Well, that's because I'm a lefty. My right hand was the one on the forearm when the rifle was fired---and did I happen to mention that my rifle is a Savage 110L? I was firing a LEFT HANDED rifle when this happened. My support hand was on the opposite side from the vent hole and still managed to get somewhat burned. So there's the lesson: imagine if it had been a right handed gun and my hand had been beside the vent hole! I'm not at all sure I wouldn't have suffered significant damage to my off hand. Owning a left handed rifle has been a relatively recent indulgence for me since I've reached middle age. I've done (and still do) most of my shooting with right handed bolt guns. In many cases they are the only ones available. If you want to shoot 98 Mausers, for instance, or 1903 Springfields then you'll be shooting RH guns. I wonder if maybe that's not such a good idea.

I know case failures are somewhat rare, but maybe once is enough. So here are all the lessons I learned:

1) Glasses, prescription or otherwise, should be on your face EVERY TIME you pull a trigger. I'm confident they spared my vision to some degree.

2) Check cases for impending head separation if they've been used more than a couple of times.

3) Maybe buying dedicated LH guns is less of an indulgence and more of a wise precaution. I'm certainly thankful this round failed when I was shooting a gun designed to vent gasses away from my hand rather than toward it.

IMG_0466.jpg
 
A couple of things, I guess. One is to check headspace against wear from years of use. That's a sort of "general principles" thing.

The other is to take a piece of piano wire and bend a 1/8" ell at the end, and sharpen it. Reaching down inside the case and scraping, the beginnings of a separation can be felt.
 
I see you posted this on another forum, and the safety precautions you mention are worth telling to all.

While you obviously had a case head separation, I cannot see enough of the case to determine if in fact you had the same symptoms as these cases:


300WSMCaseHeadSeparation1.jpg

300WSMCaseHeadSeparation2.jpg

300WSMCaseHeadSeparation4.jpg

These are someone else’s pictures, the case is a 6.5 Creedmoor.

It is unusual for a case head to fail due to stretching that far down on the case. It might very well be a brass flaw. Brass flaws happen. Cases can also rupture after exposure to ammonia. I believe these .223 cases from Scharch were exposed to ammonia.


Scharchsectioned223Rembrassblownout.jpg

LC87ScharchBrassIMG_02070424.jpg

It was good that you were using a Savage. Nicholas Brewer did an outstanding job in designing this action, he incorporated features that protect the shooter in the event of gas loss. It could have been worse. If you had a similar incident but without glasses, behind one of those military M1891, M1892, M1896 actions or the 03 Springfield, you could have lost an eye. I had two out of battery slamfires in Garands, both due to Federal primers, and I know, based on the pitting of my glasses, that I would have gotten massive amounts of brass particles in my eyes, but my glasses protected me.

Look at pictures of competitive shooters, the ones who have been shooting for a long time, they all wear protective glasses. There is a reason.
 
Too many loadings is the answer. I got lazy and didn't check to see if it was weakening at the base (see point #2 in my original post). That's exactly why they failed.

I posted it to both shooting forums I read so people will learn from my dumbness. I should probably post it cast boolets as well.
 
Lazy no excuse

With out fail I check my brass every time they are fired. Any one that doesn't shouldn't reload. Just buy new ammo to shoot. This might hurt some ones feelings. I'd rather do that then hear about some one loosing there sight.
 
I stopped having head separations the day I stopped full-length resizing for bolt rifles.

I turn the FL sizer die out until it just kisses the shoulder, and then just scare it a little further. My .308 .223 and .30-06 brass lasts until the primer pockets get loose.
 
I stopped having head separations the day I stopped full-length resizing for bolt rifles.

I turn the FL sizer die out until it just kisses the shoulder, and then just scare it a little further. My .308 .223 and .30-06 brass lasts until the primer pockets get loose.
That's what I do as well. Closing the bolt handle on my ammo actually takes a bit of effort because I make sure I don't set the shoulder back. Still, nothing lasts forever.

I suppose this could have been a piece of brass with a thin spot from the factory, since I've never had this happen before in thousands of rounds of centerfire rifle reloads.
 
I reload my brass in lots, so I can keep track of the number of loadings. I neck size only for my bolt guns, and some of the older lots are over 20 loadings with no signs of separation. I check using the bent paperclip method every 5 cases or so and have not found any issues yet. I also ultrasonic clean so I can visually check.

I'm curious to see if you have an estimate of how many loadings that brass had been subjected to so I can get a better idea of brass life. Do you have any other cases showing signs of separation?
 
Well, it wasn't thinning brass, at least not the kind normally seen from stretching due to excessive headspace or excessive full-length sizing. I sectioned the case head with my band saw and here's what it looks like:

sectionedcasehead.jpg

As you can see from the arrows, and from the corresponding side, this case wasn't anywhere near the point of separation due to sidewall thinning. The case was sectioned right through the middle of the failure area.

This brass has been loaded seven or possibly eight times. It looks pretty solid except for the place where it failed.
 
Great pictures showing what appears to be a single case failure. No discernible stretch marks from excessive headspace or over-zealous FL sizing.
You seem to be a conscientious reloader, and although you are at a top load with IMR4831, it's a proven load for you, and IMO, it's an isolated incident and likely the fault of that piece of brass.
Good shooting.


NCsmitty
 
Either a latent brass flaw or stress corrosion induced by exposure.

I have a material failure analysis book. In one case study a bronze boat propeller fell off due to exposure to bird poop.

Did the bird of paradise visit your cases?
 
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