40 S&W Case head separation

[Hounddog]

Just wanted to post up some pics of a piece of brass that I had the case head separate on. This was with a normal charge of WST. The gun did not kaboom, and the boolit still fired. The report was not normal and there was a little powder blow-back, which is what let me know there was a problem. I stopped immediately, dropped the magazine and racked the slide open to check for any problems. I had to pull the case out of the barrel with some pliers and it took a minute to find the case head on the ground. This was a PMC case that was a range pickup. Unknown number of reloads. It was a real eye opener but, like stated before, this was with a normal charge of WST. I am very meticulous with my reloading and I always visually check for powder in my rounds when I load on my LCT. I just need to be a little more thorough on my visual inspection of my cases. Wanted to post it as a safety reminder for all.

7149171492

I was amazed at the near perfect separation of the case head. Pretty scary!

Happy shooting

Hounddog

[Idz]

That case looks bulged all the way around like it fired out of battery. Could you have a stuck firing pin that fired the round before it completely chambered?

[MtGun44]

Looks like serious overpressure, from the bulge at the unsupported
area at the feed ramp. Slightly brittle brass, serious overpressure
and failure? Guessing.

I have seen an official letter from a major federal LE agency to Glock
asking why they had so many guns blowing up during training with
.40 S&W factory ammo. I was not able to see the response, but understand
that .40 S&W is a very hot cartridge and there seem to be a whole lot
more of unexplained blowups and blow outs with it than with other
semiauto cartridges.

Bill

[Shiloh]

When you sized these down, was there a shear line created?? Were the cartridges fired in a Glock with a factory barrel??
Cases with a bulge need to have it removed first. I had a guy mill the base of a size die to allow the cases to go further into the die.

A LEE carbide sizing die does the same thing faster. After market barrel cured the bulge problem.

Shiloh

[Hounddog]

These were sized in my lee sizing die. As far as wether or not they were previously fired in a glock, I couldn't honestly tell you at this point. All of my 40 s&w brass is range pickup so it very well could be. Would'nt really know unless I checked the fired primers on the brass before loading. I'm definitely going to be more cautious when inspecting this stuff. I suspect there may have been a crack or fissure down there.

Thanks
Hounddog

[Hounddog]

Also these were fired from a completely stock full size M&P 40.

Hounddog

[Shiloh]

The reason I'm asking Hounddog, is that I blew up a Glock 40 when the case failed similar to yours. Mine was hangin on by about 40% from a seperation.

Shiloh

[popper]

Had exactly the same thing happen with an old FC marked case. Scares the wits out of you when it happens. I checked the rest of the cases and they all had a micro fracture at the extractor groove, need a loupe to see it.

[Reloader06]

I would bet on out of battery. the "Bulge" the entire diameter of the case is the give away.

My 2c. YMMV

Matt

[longarm85]

^^^^^^^^ Reloader06 i'm with you looks bulged all the way around ....my vote is out of battery ....

[Reloader06]

Well Idz brought it up in the first resp once. I happen to agree.

[tomme boy]

This is why I will NEVER own a 40. If I hear or see a blown up semi auto pistol, 9 out of 10 times it is a 40 cal. I think them bulge buster dies are going to end up causing a lot more blown up guns. That brass is no good if you have to run it through a swage die like that.

[GSM]

This is why I will NEVER own a 40. If I hear or see a blown up semi auto pistol, 9 out of 10 times it is a 40 cal. I think them bulge buster dies are going to end up causing a lot more blown up guns. That brass is no good if you have to run it through a swage die like that.

+1

Not a metalurgist, but if you take a piece of metal that has reached it's yield point (bulges), squish it back to shape, you're still using a piece of metal that has yielded and may not have the strength to contain the pressure generated by the round.

[gray wolf]

Not a metalurgist, but if you take a piece of metal that has reached it's yield point (bulges), squish it back to shape, you're still using a piece of metal that has yielded and may not have the strength to contain the pressure generated by the round.
In a way I think the bulge busters create an illusion that things are OK.

[Ford SD]

With my setup I like to hand prime to check primers-- seat pressure and depth
the soft seated primer go in to the bucket for practice rounds (and for where i dont care if i loose brass)some of the matches I went to had a no pick up rule to speed up the match.

So I single stage de-prime and when I find a case that is hard to size ---> scrap bucket it goes
I find I can judge the case bulge better on a single stage

I have even found one that 90% resized --and I stopped-- pulled it out and it looked like a belted rifle case---> scrap bucket

With the odd person shooting 9mm major, I have even found a 9mm that would not go into a Rcbs shell holder --and visual problems when compared to a sized case

[35remington]

If the gun fired the round that failed with a pull of the trigger the gun was not out of battery.

Absolutely impossible to do.

[hermans]

My gut feel is also that it went off out of battery. Around here we have seen many 40 S&W's doing funnies with their brass.......in IPSC/USPSA style shooting you need to beef up the 40 S&W loads to make major PF.

[popper]

Nope, cracked case at the ejector groove. Mine looks just like that, not quite as much bulge on the case head end, 'belled' all the way around. Not OOB or glocked. Still have it in my 'reminder' bucket. Head ejected, case was still in the chamber, next round jammed, plated bullet gone. Inspect your cases and don't reload FC HS 40sw, it's a known problem! Don't have any 40 PMC brass but will look out for it. Thanks.

[Idz]

I think all agree that this is a bad thing to happen. The two suspects are the ammunition and the firearm. All of this ammunition should be checked for cracks, primer seating, OAL, and fit checked by removing the barrel and dropping each round in. If there is ANY suspicion of double-charging the whole batch should be recycled. The firearm should also be completely stripped and checked for sticky firing pin, broken firing pin, out of battery trigger pull, etc. You may not be so lucky next time!

Good Luck

[Alan in Vermont]

I haven't loaded a lot of 40 but I found really wild variations in how much effort was required, either in a normal carbide sizer or a Redding G-Rx "bulge buster. There seems to be some large variations in chamber sizes. This is apart from the "Glock Bulge" issue. It makes me think that the gunmakers are using chamber dimensions that are all over the map to get better feeding.

[tomme boy]

I have a feeling that Lee will stop making the bulge buster dies as soon as the lawsuits start hitting them. Reloading is very dangerous. But these dies are taking a piece of brass that is unsafe and trying to make it useable again.

[35remington]

Again, if the gun fired when the trigger was pulled it wasn't out of battery. Broken parts cannot enable out of battery firing when the trigger is pulled.

Ever.

[Hounddog]

If the gun did fire out of battery would there be evidence of that on the primer strike? I may have to compare the primer to other spent cases out of the gun.

[35remington]

If the gun fired when you pulled the trigger, the gun was not out of battery. Did the gun fire when you pulled the trigger? If it did then out of battery is impossible.

If more people understood how automatic pistols worked, the "out of battery" hypothesis wouldn't come up very often. Since most people are rather hazy on how pistols function, ideas like that come up from time to time.

They are not credible to explain these types of incidents.

[Hounddog]

Here's what happened. I was running some practice drills with my M&P 40 with about 50 rounds of 180tc boolits in 800x and 50 rounds of 180tc boolits in wst. I ran through all the rounds of 800x and got about two mags of wst. Popped in third mag and fired off about 10 rounds slow fire till I hit the bad round. So yes I did pull the trigger and the round went bang, however the bang sounded a little off and I noticed some powder blowback toward my face. I proceeded to drop the mag and racked the slide open. Thats when I noticed the case stuck in the barrel. I pulled the case from the barrel with pliers and field stripped the gun and inspected it. No damage done to the gun. I honestly believe this was a bad piece of brass, but am no real expert on these things. I'm just glad I didn't kill myself or damage my gun. I wanted to post this as a warning to others and to get you guy's feedback which has been a great learning experience. I love to glean as much knowledge from you guys as I can, and that's why I love this site.

Hounddog

[Hounddog]

PS

It took me about 20mins to find that casehead. The thing that amazed me the most was how perfectly it sheared along that line. It looks like it was cut with a laser or something. I have kept it on my reloading bench as a reminder of how dangerous this stuff can be and to watch my a$$.

Hounddog

[35remington]

Since you pulled the trigger for the gun to go bang, out of battery absolutely, positively did not happen.

So something else caused the case head to separate, but at least now you don't have to chase a unicorn. Stick to the possible causes now.

[243winxb]

http://s338.photobucket.com/user/joe1944usa/library/Firearms%20%20and%20%20Reloading/KABOOM
This was a PMC case that was a range pickup. Happens. The 800x will bridge in many powder measures. One case gets part of the powder charge. The next case gets 1 + If your running a maximum loading, KABOOM.

[Cane_man]

OEM bbl or drop in replacement?

[Hounddog]

OEM barrel.

[Hounddog]

Load was with WST. Not 800x. Just clarifying. 800x loads went off fine. All WST loads went off fine with the exception of this one. I did end up shooting the rest of the 50 loads of WST, and they all went off without a hitch.

Hounddog

[garym1a2]

How much WST?. A case that has a large buldge and goes thru a bulge buster gets a very weak point.

[MtGun44]

40 S&W is very high pressure round, add in all the old Glocks with massively
oversized unsupported chambers, and then bulge busting (which makes the
brass harder and MORE BRITTLE in the bulged area) and I think that I will
continue to boycott this cartridge for handloading.

IMO, making factory velocities in a .40 S&W is a lot like my old major caliber
loads in .38 Super. The load WAS in a Hodgdon loading manual, but it was
right on the edge, max and while I fired at least 75,000 of them thru
that gun, I got about 4-5 case blowouts - 100% from my missing
a WW case that got picked up at the range during competition. I had
a hard nosed reason to use those loads, I had to make a certain velocity
to compete. Now that I do not need to compete, I NEVER load that hot
in the .38 Super these days. I suggest that everyone reloading the
.40 S&W consider how bad they need to make full factory velocity,
if they are doing so. For competition, if needed, OK but realize the
risk of what was called "Super face" (tiny bloody spots in face from
brass fragments) in the old IPSC days. I only got it twice, and only
from "bad brass" - all WW brass was not up to it, Rem, PMC and
Midway headstamp would load forever, literally until the headstamp
was beaten off of the brass by ejector hits. WW would only
survive about 50% of the time. To me, letting a piece of WW brass
into my system was just like doing a double charge, it was a personal
failure to "do it correctly". Today, I will not risk it and have sorted out
and sold all the WW brass in .38 Super, plus lowered my load a good
bit, too.

I suggest that the "out of battery" folks, look at a Browning system gun and
slowly pull the slide back and watch how far it has to be back for even .020
clearance between the case head and breech face. You will be surprised, the
slide will be about .2- .3 inches back from fully forward. No way a hammer
can hit the firing pin at that slide location.

POSSIBLE to have a broken part or ultra weak spring fire a round OOB
DURING CHAMBERING, but NOT when the round was fired by pulling the trigger.

Bill

[garym1a2]

Tables I look at the 40 S&W runs about the same pressure as 9mm luger, 32-33kpsi. Where people tend to run into the most problem in USPSA and the 40 is either weaken brass or using fast powders like Clays and WST to make Major Power factor with heavy bullets.
Since I shot 40 in production class I load my 40 to low minor speed, 175 gr bullet down to 800 fps gets a rather mild load. Easier recoil than a 9mm. Try to make that 175 gr run major with WST you need about 950fps. This speed is popular with WST in major classes but right on the edge.

[35remington]

Even "hammerless" guns like the M & P and Glock cannot fire out of battery with a pull of the trigger because the sear notch is out of reach of the sear when the gun is out of battery. Everything can be broken, safetywise, and the gun still will not fire out of battery with a trigger pull. In addition, the M & P has an additional mechanism that prevents trigger firing when out of battery. Flip the slide over when it's off the gun and look for it.....it appears as a pin in the slide similar to the Colt Series 80 system.

That's called the "belt and suspenders" approach to preventing out of battery firing with a pull of the trigger. And it works, each and every time, without fail.

[Mont1120]

Beyond a shadow of a doubt this is not caused by a case bulge having been shot in a Glock. I had to send my XDM into get repaired two times because of this same blow up. I have successfully recreated the issue and it is absolutely PMC brass, and with my reloads it is 180 grain lead. If you examine it closely under a high power mag glass, you can see what looks like a gap between the ejector rim and the case rim. None of the Speer, RP, or other brass has this same line appearance. I just blew one up today after checking all my brass twice before shooting.
It does not happen with plated or jacketed bullets. For this I have no explanation other than a weird spike in pressure that should not be there. I can fire the same 180 cast bullet in any other brass except PMC. Throw all PMC out. Do not trust it.

Mont1120

[cgt]

I just loaded 50 rds of 40 at 5.5 to 5.6 unique powder. 180gr bullet jacketed hp from berry oal is 1.118 to 1.120
Im little long on oal. Should this load be safe? Just looked and its pmc brass. Is my last load on this brass and then using the 1k starlines sitting in the drawer.
Xd40 4"brl

[MarkP]

Could be due to a cold shut during the heading process. Similar to a forging lap.

[Garyshome]

I use Dillon dies and have no problems with range brass Yet.

[tomme boy]

Unsupported chamber. That is the problem. Certain types of brass may be more of a problem than others, but it still comes back to an unsupported chamber that causes this.

[MarkP]

This is likely due to a cold shut the two attached pictures show a section view of a 40 S&W case; the zoomed detail has a typical flaw drawn in magenta. The material folds over rather then flows, similar to a forge lap. If the flaw zippers open, the failure is very similar to the picture shown in the original post.8429584296

[fredj338]

You answered you own question. Range brass of unknown abuse can let go at anytime w/ a normal load. The 40 is one where I probably wouldn't use range pickups, too many guys are hot loading it & stressing the brass. If it has any guppy shape to it, toss it.