Pistol case head separation

Cerdan

Cerdan

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I think I already know the answer to my question (a couple of CGNners have told me privately that there's no such thing) but I'm looking for some definite confirmation here. Can this actually happen under normal circumstances? Has it happened to any of you? I'm not talking about that time you double-charged and the case blew out at the feed ramp, but from normal wear...

I've been handloading for a bit under a year now, I've got some 10,000 rounds under my (bullet)belt, and every time a case has died on me, it did so quite harmlessly by splitting at the mouth. I'm starting to think that's how all my pistol cases will die, so I'm becoming a bit more lax when inspecting cases, but am I fooling myself? Is there a risk of a pistol case separating at the head and causing a bit of unpleasantness?
 
Case head separation happens in bottleneck cases, either from excess headspace or repeated grow/trim cycles. Neither concept exists in straight-wall pistol cases, so I expect it can't happen.
 
I would think it would be extremely unlikely.

Case head separations in bottleneck cases are caused by brass flowing forward, which is why you have to trim. This doesn't really happen with straight walled pistol cases, so you would more likely see them fail by the mouth splitting. If you are reloading for auto pistols, you will probably lose the brass before you wear it out.
 
I have been shooting & reloading for many years & have seen a few cases let go at the rear base.

In every situation is was caused by excess pressure ( reloading error ) and in only 2 types of guns. Both of these guns have barrels with a portion not supported just ahead of the feeding ramp . Glocks & some 1911's.

Can it happen under normal circumstances ? I would say ( IMO ) not very likely.
 
Its very rare with straight cases but can happen.

A saw a fellow last week with a .460 who had 2 cases seperate about a third of the way up from the rim. From what I understood they were Hornady cases and had been loaded on 2 or 3 times. Almost looked like a manufacturing flaw but its hard to know for sure what the cause could have been. The failed cases caused no problem at all and weren't noticed till he was ejecting the brass but its still not a thing you want to see with any gun let alone one with that kind of power.
 
actually, i've HAD IT HAPPEN- just ahead of the extractor groove, in 45acp, took the tit off the slide stop- found the spent case and there it was- but there was no catastrophic BOOM or anything else- only thing that happened was to the slide stop
 
some cases with a knerl groove about half way up the case will let go there and will leave part of the case in the chamber , I've only seen it on .45 acp cases and the were getting quite used.
 
Not in hand gun cases, but I've had it hapen in my 300 win mag. This was because I was using the cases many many times. I got 14 loads out of some of them. Fortunately, I have the tools to quickly remove the remainder of the case after the head has come off. It's probably not going to be a simple task for the average Joe and may involve a trip to a gunsmith.
 
I think it might be conceivable if the pistol case was undersized over a number of firings. I'm thinking here of .38 Special cases trimmed short for use in .38 S&W's. If the .38 Special case was resized in a .38 Special die after each subsequent firing in the S&W chamber, I think the possibility exists. It does not seem reasonable otherwise, and I have not experienced it.
 
Gotta go with Acrashb on this one.
The only pistol cases I have had separate were 256win in a Ruger Hawkeye.
That is excluding T/C contender with bottleneck cartridges.
A straight wall case will neck split looooooong before separation.
thegunnut
 
Thanks for the useful thread, was wondering about this myself. :)

Although, I will still be inclined to give a once over of the once fired brass coming from unknown sources (aka, other than me)
 
eh class said:
some cases with a knerl groove about half way up the case will let go there and will leave part of the case in the chamber , I've only seen it on .45 acp cases and the were getting quite used.
Click to expand...

I have seen this particular instance also. The grove is actually a form of crimp, I believe. I'm pretty sure the crack in this location is caused by work hardened brass, not because of any thinning due to stretching.

I don't think there is any way to actually thin the web area on a straight walled case. I suppose there is always the posibility of a defective piece of brass though.
 
I have had a "classic head separation" in a batch of Remington 44 mag brass (was waay back in the mid 1980's. Regrettably I have no pics and no samples of the cases left--it happened to 3 or 4 out of a batch of 100 cases on the 4th or 5th reloading.

Is the only time I ever had it happen in a straight wall case.

The only bottle-neck case I have had trouble with was cases fired in one paticular 300 h and h rifle I had.

44Bore
 
For years I was with the it-couldn't-happen-with-a-straight-walled-case crowd. I even read where part of the trouble Custer had at the Little Big Horn, was that the cases seperated in the 45-70 carbines they were using (I think with 60 grains of powder), with the case wall staying in the rifle and putting it out of commission.
I didn't believe that story. Straight walled cases couldn't come apart, I thought.
Then, and I've told this before on these threads, we were in Arizona at the location of an early fort and we found their shooting range. We picked up quite a few 45-70 empties, and lo and behold, many of them had seperated about 3/8 inch from the base!!
This picure shows several examples of it.
P1020217.jpg
 
Lo and behold, those are balloon-head cases not exactly the most robust design for use in dirty chambers in the midst of defending a fort.;)
 
Cerdan said:
I've been handloading for a bit under a year now, I've got some 10,000 rounds under my (bullet)belt, and every time a case has died on me, it did so quite harmlessly by splitting at the mouth. I'm starting to think that's how all my pistol cases will die, so I'm becoming a bit more lax when inspecting cases, but am I fooling myself? Is there a risk of a pistol case separating at the head and causing a bit of unpleasantness?
Click to expand...

Hmmm...

I was going to say that I have heard of head separations in straight-wall cases. Rather recently, in fact, and on these very forums. So, I went and looked, and lo and behold:
http://www.canadiangunnutz.com/forum/showthread.php?t=289952&highlight=separation

Which, begs the question, Cerdan, which is it? Are you experiencing case head separations, or are all your cases splitting at the mouth? You are contradicting yourself.
 
Look at the picture again, do you really believe those cases separated at the head? I surely don't. From what I've gathered from the responses I got in that other thread, I probably have chamber spec issues in that particular gun. I believe those case failures are due to an entirely different phenomenon than "true" case head separation. Case in point, like some posters explained on the previous page, cases separate at the head because of thinning at the web due to metal flowing upward, but these cases were almost new. What's more, I understand that "true" case head separations are very dangerous and quite dramatic when they happen. Like vagrantviking said on the previous page in the case of his buddy's .460, these case failures went largely unnoticed until ejection. For those reasons I chose not to encumber my initial post by mentioning an exceptional situation.

But thanks for stopping by and confronting me about my seemingly duplicitous post. You're quite the Internet hero.

And thanks to everyone who took the time to make real contributions to this thread. Once again, it seems hard to generate any kind of firm consensus on any issue, but at least everyone seems to agree that, barring excessive pressures, case head separation in straight-walled cases is rare at best.

Still, I wonder whether if I should stop doing what I've been doing since I started reloading, ie reusing cases until they split at the mouth. That method has served me well, but I'm honest enough to realize that just because nothing bad ever happened to me doesn't mean I'm doing everything right. It could just mean I'm luckier than most.:yingyang:
 
H4831 said:
Then, and I've told this before on these threads, we were in Arizona at the location of an early fort and we found their shooting range. We picked up quite a few 45-70 empties, and lo and behold, many of them had seperated about 3/8 inch from the base!!
Click to expand...
Interesting.. Would you agree though that these aren't examples of "classic" case head separation like one would see in bottleneck cases and are likely due, like joe said, to a lack of robustness or other possible flaw?

I'm just trying to wrap my brain around the physics of it all I guess...

joe-nwt said:
I suppose there is always the posibility of a defective piece of brass though.
Click to expand...
That's precisely the distinction I'm trying to make here. Defective brass or out-of-spec chambers will always cause problems, that's just part of the game. I think you and I agree, though, that there's no reason for a safely-loaded, structurally sound piece of brass fired in a well-designed chamber to separate at the head, even after multiple loadings.
 
The only ones I've seen were of balloon-head construction.

Watch out for old .45 Colt and old (wartime) 9x19mm.
 
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