Case rupture - What did I do wrong???

Brass: Unfired Starline
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Contact Starline!!!

This does not look like other case separations I have seen. This was not caused by brass that had been fired too many times and just failed. Look at where the brass failed, Check your other cases for a thin spot!

This LOOKS like defective brass to me, and Starline is the people to talk to about it.

Your load is within published data , I wouldn't worry about reducing it (at this point) unless you want to...

Check with the maker, let us know how they respond. (and put that batch of brass, loaded, unfired and fired aside for now, until you know more. The flaw could only be in those two cases, OR it could be in many more, that haven't been found yet. Play it safe.)
 
Maybe it's just the lighting but are those nickle plated? I see regular brass in the pics but the ones that are separated look like nickle.

I'm gonna have to agree with others that said its a case failure and to contact Starline to get their opinion. Look inside other fired cases in the same spot and look for a ring around the inside. If you see it, don't fire any more as you don't want to damage your pistol.

Dufus summed it up pretty good, primers look good and don't show pressure signs. When people say that they will be flat, they'll be flat and fill out the primer pocket. That or they'll just fall out of the pocket from being flattened and the pressure trying to push them out. Also do like he said and reduce your charge but check your manual so that it's not to low.

Back to nickle, I don't like using it as it doesn't spring back as much as brass and isn't as pliable either. Making it prone to being brittle and the way the cases look made me think of it. Even if they are new, the process of running them through the dies could've made a weak point weak enough to split.
 
Take a new case and carefully cut in half lengthwise . Check dimensions.
Clean and check the chamber dimensions.If the gun is unlocking while pressures are still high that might do it .
 
Chamber

I am not an expert in this, but as we all know, that kind of case failure in straight wall pistol cases is very rare, and almost unheard of in quality new brass. I absolutely would contact Starline and get their thoughts on it.

But if those are brand new cases, once fired, they look TERRIBLE to me. In a couple of the pictures, your chamber looks absolutely filthy - way too dirty for 25 rounds if the gun was actually clean when you started. And in the bottom left picture, the brass clearly shows physical damage from something pressing on it - looks kinda like three little punch marks. I would seriously consider having a gunsmith look at that chamber.

Finally, the top middle picture looks like the fired brass is visibly ballooned in the bottom half, but not the top. It is probably a trick of the photograph, but if it is actually expanded significantly more on the bottom than the top, I would again be worried about that chamber. Maybe it is normal; I do not know. I have never had reason to measure my once fired brass that closely to compare it with what I think I see here.

And Yes, headspace problems CAN cause this. Pistol cases headspace on the case mouth, and if they go into the chamber so far that there is significant room between the bolt and the case head, then the act of firing can cause the front of the case to "anchor" to the chamber walls while it is trying to release the bullet, and the rear of the case is pushed backwards into the bolt face. If that is what caused this failure in your gun, then it is an extreme problem, and I would not consider the gun safe to shoot. Your bottom middle picture looks to me that you have massively excess headspace - again this is quite possibly just a trick of the photograph, but it sure looks to me that the case head is WAY below the face of that breach (see the images below). Of course, it all depends on the actual shape of the bolt face. Once again, you need to find a good qualified gunsmith.

image002.jpg

pistolacpheadspace_zps352b6a51.jpg


I doubt the problem is the brass, and I doubt it is the load. Whatever that gun is, I sure would not want it.
 
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Do you have any other brass to try? That would isolate or exonerate the primary suspect.

I'm also suspicious of the gun, since it's the first time you fired it. Is this a new (meaning un-used) gun?
 
To see a separation is troublesome. But to see more than one in a single batch of specific brass. That is unusual. Time to: "Nip it in the bud."_ Cull those Starline. Shoot some other Federal or other popular brand of brass. Apparently Starline's product reputation is not impeccable from what I see.
 
To see a separation is troublesome. But to see more than one in a single batch of specific brass. That is unusual. Time to: "Nip it in the bud."_ Cull those Starline. Shoot some other Federal or other popular brand of brass. Apparently Starline's product reputation is not impeccable from what I see.
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I think the problem was caused by something I did, or perhaps failed to do. I will try some once fired brass I have in the pile just to remove that variable but I really don't think Starline is at fault here.
 
When encountering a high pressure rifle load (bottle neck case), the brass expands, but does not retract. This results in a hard to open bolt. I have seen some that require a rubber mallet to beat on the bolt handle.

A high pressure experience in a revolver results in very herd extraction of the fired case. I have seen the need to use a dowel and a mallet to drive the case from the cylinder.

A semi-auto pistol experience with high pressures will most time rupture the case in the area of the case head. When the brass expands and does not spring back, the pistol might fail to cycle because of the stuck case, the extractor might break a piece of the rim when trying to cycle, or the thinnest front part of the case can be separated from the thicker lower half of the case.

This occurs with a longer case (as here with the 10 mm) more so than a short case as with 9x19 or even the venerable 45 ACP.

I have witnessed all these incidents more than once.

Lower your charge weight, but do not lower below the recommended start loads. Doing so might cause the pistol to not cycle upon firing.
 
I'm wondering if I didn't over crimp
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No that's not your problem.

I didn't. measuring a few now I see that some are off by one thousandth of an inch. I'm embarrassed to say this but I didn't even know I needed a headspace gauge.
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The .001 difference in length is nothing. That equates to 1/3rd the thickness of a human hair. The barrel on your gun is a sufficient head space gauge. the plunk test will tell you if you are having problems with head space. Keep an eye on your overall length (OAL). As suggested go to the powder makers web site for your double check you powder weights for your bullet weight
 
Do you have any other brass to try? That would isolate or exonerate the primary suspect.

I'm also suspicious of the gun, since it's the first time you fired it. Is this a new (meaning un-used) gun?
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I have some once fired brass I can try. The gun is used but it's new to me. I just got it last week. This was the first time I fired it but it's been fired before.
 
Hmmmmmmmm!
Let me throw this out there for ya.
Look at the brass outside wall.
It is scored all to hell and back.
There are also a few dimples right below the case mouth that should not be there.
I’ve seen this once before where the owner had run nothing but steel cased ammo and the chamber was scratched and scored and left brass case ammo looking just like what the OP has.
That gun would rip brass apart unless it was down loaded to the bottom of the loading table. The bad thing was loaded that low the case did not expand well enough to seal the badly scored chamber.
Same scenario as the OP.
The gun was new to this guy too.
 
Dufus, you're telling me that out of the thousands of .45, 9mm. makarovs, and other military things that were cranked out over the years, there haven't been numerous chambers that were bored terribly, and left with reamer rings, just the thing to lock a case in so hard that it should have done that exact thing? It would be just like a threaded bolt on a nut.

Of course rough chambers exist. but we're talking about dirt being enough to pull a casing apart at the center, ripping it in half because there was resistance. I'm just not believing that is possible. As I said, how often has anyone seen a case ripped in half on a reloading die that was stuck? NEVER, EVER HEARD OF IT. Doesn't the brass usually tear apart at the shell holder?

Not at all the same situation, being as the case head was pushed apart, maybe, but there doesn't seem to be any indication that it was pulled apart when the extractor yanked it out when the recoil pulled the slide back. but still, it's a matter of that case head being pulled apart at the middle and that just doesn't make sense, since the entire case should have had equal pressure all the way front to back. Yes, there is a slight taper, but even that doesn't appear to make sense. Why did it happen in that place, in a perfect ruing, just because it was tapered?

Everyone knows that brass is malleable. It stretches every direction when fired. I'm not seeing any evidence of stretching at all, just complete and simple failure in a perfect ring.

Am I the only one that is seeing two rings on that loaded round? one at the base of the bulet, and a faint one right where the tear started?

One last question. Does the recoil action actually start before the round has left the chamber? Never mind, I just looked it up, the bullet is long underway, that pressure should have been vented, and any pressure that remained on the walls of the brass should have been gone.

I don't think that this is the answer.

http://www.thefirearmblog.com/blog/2015/08/18/1911-fired-at-73000-frames-per-second/
 
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I have come up with two more questions. First, measure the length of ever case you have, all you have to do is line them up and put a straight edge over the top. Are any of them significantly shorter, short enough that they could have been driven a little bit farther into the chamber, thus allowing the case head to be forced back while the pressure is still at peak? Check the chamber, any way you can, and find out, do you think that the chamber is cut too long, long enough that the firing pin could drive it in too deep, again, allowing the case head to be driven back while still under full pressure?

Of course, this still depends etirely upon the extractor being so loose that the cartridge can be forced into the chamber so far that this sort of scenario could happen.

No matter how I look at this, I still keep coming up empty for explanations that can actually work, except for a flaw in the brass. Even that seems crazy, what sort of flaw could cause that to happen, and how would it occur during the drawing and cupping process? How would it happen without happening to tens of thousands of other pieces as the lot is run, and why hasn't the world heard about a recall on the brass?

the only thing that really seems reasonable is if that case mouth was jammed far enough into the leades, or chamber opening, that the bullet actually locked it into place, and the bullet grabbed onto it and pulled it forward, ripping the front off of the case as it started up the barrel. Still, where are the signs that this is the answer? no heavy ring at the front of the case, no rifling marks, nothing at all seems out of the ordinary up there.

Since this is a new pistol, now that I know that, maybe it's something strange with the pistol and not the brass, but heck, I can't figure that out either! the gun has to go back to smith and wesson, I believe, for examination. This is just so weird that i think you need to look at all of the things involved.
 
A thing that you can do to find out of the chamber is so scratched up or pitted that you may have this happen would be to run a few cotton balls into it and see if it pulls the fibers around. Take a dry patch, and wrap so many of them onto a rod that you have to really, really force it in. Can you move it back and forth, or is it sticky, like your chamber is too rough to let it move? Visual inspection matters too. Whether you send it to smith or not, a gunsmith should probably check chamber dimensions. If it is rough he can polish it.

If you want to section some brass, or even bullets, the way I would suggest doing it is with either a belt or disc sander. Rather than trying to slice a piece off with some sort of saw, and getting unbelievably rough edges, just grind off whatever portion you need to remove. Yes, the thing will get hot, it's going to be hard to hold it, it's not going to be easy, but in my experience, there is no good way to get that job done otherwise that is as quick and safe.
 
OP said its a used pistol but new to him.

OP, you said that the pistol wouldn't fully chamber a round after the last two? Have you taken a bright light and looked into the chamber? Make sure there isn't a piece of brass smashed into the front of it.

Those little dents in the one case could've been from the first case coming apart or from another case. Look well and try dropping a round in the barrel while it's out of the pistol, if it doesn't drop in properly, look harder. Or run a bore brush through the barrel and see if anything drops out.
 
Good idea. I keep forgetting the little things. It wouldn't have to be a ring of brass, could be a shaving off of a bullet.

BTW, I keep thinking that those dimples are essentially pieces of unburned ball powder. Isn't the powder used ball? So if there was an overpressure situation from an excessive load, all throughout the batch of loads, is it likely that there would be flakes of powder left in the chamber by previous rounds? Things just still don't make sense.
 
"...max for this combo is 12 grains..." Not according to Accurate. 11.0 is max for a 180. 1 grain wouldn't cause that anyway. Neither will any kind of crimp. Far more likely to be a flawed case. Like 44 AMP et al say, contact Starline.
 
OK maybe I am crazy but does anyone see how scored that case is?
Also look at the pictures with the new un-fired primer.
That is an un-fired case and the brass is badly scored.
This is new brass per the OP.
I have bought thousands of rounds of brass from Star line and all have been slick and mirror finishes.
He shot 23 rounds and 24 & 25 failed.
Now I am starting to wounder if we don’t have more than one issue in play here.
Lets say we have a sizing die that is a little on the tight side.
We have a slightly worn chamber.
And we have 2 pieces of brass that were just a little thin in the middle.
Even with the correct charge weight we have a round that is a little small and a chamber a little on the big side with a couple of pieces of brass that under normal circumstances would not have an issue.
When fired we could very well see the same results as the OP.
Brass has over expanded and separated.
Like the OP stated these were the last 2 rounds fire.
A circle does not get smaller when heated it grows bigger.
If he fired 23 rounds with in a 2-4 seconds pause between rounds the chamber could have grown more than a thousands of an inch thus leaving the OP with now a very large chamber.
I am just throwing things out there to consider based on the pictures I see when magnified.
 
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