This got my attention yesterday

by James Hensler 11/16/2020, 11:34 am

First topic message reminder :

This got my attention yesterday - Page 2 Cb82fb10

I have been reloading since I was a young boy and now I am almost 52. This is the Second case that has ever ruptured on me and I have the other case somewhere. The split it where it is not supported at the bottom of the barrel. The energy blew down and out the grip each time. Both magazines needed rebuilt but the mag frames are good to go. The 1st time this happened I did get cuts on my face but this time I didn’t!

by James Hensler 11/17/2020, 5:38 pm

My stuff is all Winchester with 500 once fired Starline! I can tell you this 1911 has had over 125k rounds threw it in 4 years. This year I didn’t get to shoot hardly at all or it would have had 20k more

Phil I knew your barrel would be the same because everyone I have ever owned looks the same way.

There is a reason that reloading manufacturers have a pressure station on their machines! They are checking that bend in the case to try to prevent it from ever happening.

by GrumpyOldMan 12/3/2020, 6:07 pm

Been around the block a few times and from the indeterminate but large number of reloads J.H. reports, this appears to be a simple case failure. Most likely metal fatigue from repeated firing cycles. AKA work-hardening. As in, even copper=based alloys can lose their bendiness and become brittle.

Unlikely to be embrittlement from exposure to ammonia or mercury, but the ammonia factor cannot be ignored without knowing more about the case "hygiene" habits. Mercury isn't in primers for more than a century and few home workshops have any to get loose anyway.

Yes, the standard 1911 chamber is unsupported at that portion of the case wall. No problem with mid-pressure cartridges like .45 ACP. Less problem with .38 Super. Can become a problem with .38 Super loaded to the old USPSA Major Power Factor of 175, especially with the wrong powders and/or too much charge weight variation and/or bullet setback on chambering and/or a lookalike heavier bullet getting into the batch.

But that hot-rod problem with case-blowouts is why the ramped barrel with fully supported chamber became a thing.

The lack of destructive power from the gas blowing down the magazine well points conclusively in my opinion to no double-charge or other defect in assembling the handholds.

There's a guy named Clark (Clarke?) over on a couple of boards I used to frequent whose hobbies included buying cheap handguns and overloading them to failure. Usually it was the case in semi autos. Might want to consider asking him to reload the same case 200 times to see when and how he can get a .45 ACP case to fail. He uses tethered firing arrangements with all appropriate precautions. Choose the case brand that is thinnest just ahead of the case web.

Heard of some high-volume USPSA shooters retiring their brass when the head stamp rubs off. Can we see a pic of those two misbehaving cases' headstamps?

by mpolans 12/4/2020, 1:00 am

James Hensler wrote:Oh no chance of a double charge because this was my long line match loads. I use a tray of 50 and my Rcbs trickle charge. Just a wore out case it happens. The primer is still in place and doesn’t ever look bad. This was my 5 shot of the string.
1st shot x at 8 o’clock
2nd shot 10 at 12
3rd shot was 10 at 12
4th shot was a 9 at 12
I reload my mags after the 4th shot so I have a full mag when it went boom and it’s not really a boom kinda just sounds odd

So where was the 5th shot? Laughing

by James Hensler 12/4/2020, 5:58 am

6 at 9 o’clock

by jjfitch 12/4/2020, 9:42 am

This got my attention yesterday - Page 2 Baloon10

Head stamp?

I have seen similar "blow outs" from "balloon head" cases and "normal" loadings! Smile

by Plunker 12/6/2020, 5:57 pm

James,

Is this Star brass by any chance?

by James Hensler 12/7/2020, 6:42 pm

No it’s range brass that I sorted and the head stamps are all Winchester. They are just wore out nothing more I have used them for 3 years

by Slamfire 12/7/2020, 9:19 pm

James Hensler wrote:No it’s range brass that I sorted and the head stamps are all Winchester. They are just wore out nothing more I have used them for 3 years

I would like to know what was your powder charge and how old is your powder. Do not want to offer an early opinion on this, as I might have egg on my face.

But, I had a case head blow out, last year I think, on my RIA 1911.

This got my attention yesterday - Page 2 W2d4YUL

This got my attention yesterday - Page 2 W2d4YUL

Those beautiful cocobolo grips were cracked when the case head blew. Boo, hoo!

new grips

This got my attention yesterday - Page 2 EXaNiOt

I was firing a 230 FMJ in small primer brass with 7.8 grain AA#5, which chronographed just at 800 fps. That is not a hot load. This pistol has a habit of pushing the bullet in the case, and I think that is the mostly likely cause, as I shot up all the rest of my 7.8 grain AA#5 load without any kabooms. However, I did have one high pressure round with super carefully loaded 230 FMJ with 7.5 grs AA#5, which is even lower pressure than the case head blow. The slide was jammed back and the primer had flowed into the primer hole. Luckily, no blown case head.

This got my attention yesterday - Page 2 IdUGn2k

This got my attention yesterday - Page 2 IdUGn2k

A comment, these modern pistols can survive accidents that would blow a GI pistol all to heck. A WW2 era pistol had a 1030 frame and a 1050 slide. The slide was heated treated for the first two inches back from the muzzle, but no further! No one should ever dream that GI pistols were made of Wakandan Vibranium, forged by Dwarfs under the mystical Ice Mountains. The materials used were the cheapest, low grade steels that could be used, and still have a pistol fire 6000 rounds before a rebuild. My RIA has a 4140 bar stock slide and a 4140 cast frame, and these steels will survive accidents that will bend and bow a GI pistol.

This got my attention yesterday - Page 2 46leF1W

This got my attention yesterday - Page 2 46leF1W

All I had to do with the case head blow was clear the pistol, remove the slide from the frame, wipe all the powder residue out, re oil, reassemble, and go on shooting. Basically did the same with the over pressure primer in the firing pin hole.

One thing I noticed with this RIA was that rounds had a clunk, clunk feel as they fed into the chamber. I was sure the magazine release was holding the magazine too low and the bullets were hitting the frame or barrel feed ramp. The cure was an EGW higher magazine release. I have shot several 50 caliber ammunition cans through this pistol and to date, no high pressure incidents, and no kabooms!

Given that we all have had rounds tilt and jam, with perfectly good magazines and guns, I believe there is always the possibility of a bullet nose diving on the ramp and seating the bullet deep. And that raises pressures. Maybe you did nothing wrong. Maybe the cause was just one of those things.

I would still like to hear about the type and age of the gunpowder you are using.

by James Hensler 12/8/2020, 6:54 am

Powder was weeks old, primers as well,
185 Zero JHP
4.5 grains of N310
1.200 OAL

Guy it was just worn out brass. Look at a 45 case it blew out right where the bend is.

I just clean my pistol and put on a new grip

by Slamfire 12/8/2020, 9:30 am

James Hensler wrote:Powder was weeks old, primers as well,
185 Zero JHP
4.5 grains of N310
1.200 OAL

Guy it was just worn out brass. Look at a 45 case it blew out right where the bend is.

I just clean my pistol and put on a new grip

Could have been old brass with a brass flaw. Ammunition designers and ammunition makers did not design or make this stuff with the expectation that it was going to be re used. Whatever margins are in the case, are for one firing.

by James Hensler 12/8/2020, 10:49 am

Slamfire wrote:
James Hensler wrote:Powder was weeks old, primers as well,
185 Zero JHP
4.5 grains of N310
1.200 OAL

Guy it was just worn out brass. Look at a 45 case it blew out right where the bend is.

I just clean my pistol and put on a new grip

Could have been old brass with a brass flaw. Ammunition designers and ammunition makers did not design or make this stuff with the expectation that it was going to be re used. Whatever margins are in the case, are for one firing.

I 100% agree

by **Wobbley** 12/8/2020, 11:01 am

I

Slamfire wrote:
James Hensler wrote:Powder was weeks old, primers as well,
185 Zero JHP
4.5 grains of N310
1.200 OAL

Guy it was just worn out brass. Look at a 45 case it blew out right where the bend is.

I just clean my pistol and put on a new grip

Could have been old brass with a brass flaw. Ammunition designers and ammunition makers did not design or make this stuff with the expectation that it was going to be re used. Whatever margins are in the case, are for one firing.

Well the ammo companies sell brass for reloading purposes, so I really doubt that the cases only have margin for one firing. That’s not how metals work anyway.

by Slamfire 12/9/2020, 9:09 am

Wobbley wrote:
Well the ammo companies sell brass for reloading purposes, so I really doubt that the cases only have margin for one firing. That’s not how metals work anyway.

Call them up. I called Federal. Specifically ask them how many reloads do they design, manufacture and guarantee their brass.

I have not called Starline, they are in the brass reloading business. I would bet they simply would state:"We make good brass, it is reloaded all the time, do you want to buy our brass". I am quite certain they have never analyzed the affects of firing,hoop or radially stresses on their brass as it work hardens. I would be interested in such an analysis, but I have not seen it. Ever.

You ought to see the testing that goes on fire extinguishers. Fire extinguishers have a test by date for structural reasons.

Fire extinguishers are put into a water filled, very thick, steel tank. The fire extinguisher is filled with water than pressure tested. Water leaves the tank as the fire extinguisher expands, and that water is collected and measured

This got my attention yesterday - Page 2 YDSQhRy

This got my attention yesterday - Page 2 YDSQhRy

There are criteria for allowable expansion and contraction of the fire extinguisher. This is the water tank, the fire extinguisher is bolted inside and the worker is at a station away from this device.

This got my attention yesterday - Page 2 5ugF0Bi

This got my attention yesterday - Page 2 5ugF0Bi

This is the plastic valve that is designed to rupture if a fire extinguisher fails the pressure test. Water is vented away from the worker and the work bench.

This got my attention yesterday - Page 2 DwrPeEr

This got my attention yesterday - Page 2 DwrPeEr

This wall is where the water goes. Notice the paint removed from previous fire extinguisher blow outs! Many fire extinguishers fail the expansion contraction criteria, and, the occasional fire extinguisher ruptures.

This got my attention yesterday - Page 2 PtvKLgg

This got my attention yesterday - Page 2 PtvKLgg

I have found one account of a fatality where a man carrying a fire extinguisher died from the thing structurally failed in his hand. Bet you never thought about that pressure bottle in the corner as having a shelf life.

I contend, cartridge designers calculated the stresses in their cases for one firing, and added margin to allow for differences in brass composition, thickness, and hardness.

by **Wobbley** 12/9/2020, 12:08 pm

I spent 30+ years designing and analyzing all kinds of things that make up these gizmos. I think I understand proof testing and metal reaction to load.

This got my attention yesterday - Page 2 50963b10

by Slamfire 12/9/2020, 12:59 pm

Wobbley wrote:I spent 30+ years designing and analyzing all kinds of things that make up these gizmos. I think I understand proof testing and metal reaction to load.

Very good background, therefore you should be answer the question which has been brought up in this thread:

What is the design firing lifetime of a cartridge case, and how did they calculate it?

by **Wobbley** 12/9/2020, 1:57 pm

They didn’t most likely. Because the failure mechanism of a cartridge case is best done by low cycle fracture mechanics which is more statistically based than classic engineering analysis. Fatigue analysis starts at about 1000 stress cycles, fracture mechanics can have fewer ctpycles but you need to inspect or test for signs of failure.

http://www.massreloading.com/loading45ACP.html

And other tests like this have too low of a cycle count to get meaningful data. Not to mention the different gun designs and their effects on these analyses....

by Jon Eulette 12/9/2020, 3:09 pm

Another factor is chamber size and barrel feed ramp support or lack of. Some chambers run fat and and some feed ramps were cut too deep and the case has little support at the web. Combined both of these issues can lead to weakened brass wall and early failure. The overstretched case from oversized chamber and then resized is moving the case wall considerably. Like I previously stated, I load the cases until they are lost or split. I’ve only had one case rupture and it was 100% my fault. The pressures we run our mouse loads at are minimal in comparison to what a maximum load pressure is. I have lots of Federal brass that I’ve been using for 20 years and it’s still going strong. I threw a split case away the other day while I was reloading. A mechanical engineer buddy described a guns chamber as a pressure vessel to me. Basically the chamber/barrel walls are containing the pressure. The breechface is supporting the case bottom which is pretty stout. The barrel feed ramp is the weak link in the system; lack of support for case wall (this is why case web is thicker here by design). We know fully supported barrels were made for this reason as well as Jim Clark doing it for feeding 38 special in early pistols. If I did not know any details about the ruptured case other than the photo, I would say double charge. Easy to double charge a light load. I’ve personally never seen a rupture like this that wasn’t related to a reloading error. My 2 cents.
Jon

by James Hensler 12/9/2020, 5:04 pm

Well the one from 25 years ago must have been a Winchester bad load because it was a factory load

by Slamfire 12/9/2020, 6:36 pm

Wobbley wrote:They didn’t most likely. Because the failure mechanism of a cartridge case is best done by low cycle fracture mechanics which is more statistically based than classic engineering analysis. Fatigue analysis starts at about 1000 stress cycles, fracture mechanics can have fewer ctpycles but you need to inspect or test for signs of failure.

http://www.massreloading.com/loading45ACP.html

And other tests like this have too low of a cycle count to get meaningful data. Not to mention the different gun designs and their effects on these analyses....

Thanks!. Obviously cases do last more than one firing, and I have looked all over the place for books on case design and come up dry. There is material on artillery shells, virtually nothing on small arms cartridges. Analyses I want to know have to do with taper, case head strength, shoulder angles, magazine feed, sidewall thickness, etc. Probably some more if I could think of them.

Tell you what, the 45 ACP case was before Von Mises. Whatever analyses were conducted were done on a slide rule and probably used a simple shear failure mechanism. The data they had would have been hard, half hard, quarter hard brass material property data. I don't remember when fatigue analysis arrived, I think WW1 was just at the time of fracture analysis. And the drawings were done by hand. Remember draftsmen?, guys with ink pens, drafting boards, rulers. What they created were mechanical works of art.

by GrumpyOldMan 12/9/2020, 7:00 pm

Bottom line on one subject IMO:

Reloading small arms cartridges has too many post-manufacturing variables for meaningful design/failure predictions and statistical failure analysis. Witness Federal's re-design on .40 S&W cases shortly after the Glock kB! phenomenon arose decades ago. Whoever has the old GunZone archives can give you some great reading on that.

James Hensler's reloading practices are more irrelevant to the recent failure than Winchester's charge weight control systems. Anyone who can't wrap their head around the one in a million or less frequent metal defect ignores a small but very important part of reality.

James Hensler and Wobbley are really smart and well-informed.

Even with the lessons of the de Havilland Comet of BOAC Flight 781 (and a couple of other in-flight breakups), repeated metal stress failures are hard to predict. But we are a lot better at preventing them now than in the 1950s. And during the Apollo Program. And it goes on.

Wikipedia lets me confirm and get useful details from all sorts of crap I read about during my public education days. Stuff NOT part of the curriculum. Reading too much has some benefits to understanding the world.

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