How catastrophic is brass failure?


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Bullseye25
December 15, 2012, 02:55 PM
I've reloaded about 3-4k of .40 and I keep reusing my brass with out tracking it much. I keep load in the medium to light range and my brass hasn't showed any signs of stress.

My question is: how catastrophic is a case head separation or other brass failures? Is it similar to over pressure situations? Any potential damage to my firearms?

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rcmodel
December 15, 2012, 03:01 PM
You will not get a case head separation with straight-wall pistol brass.

If brass fails, it will blow out at the unsupported section of the feed ramp.

And it is catastrophic enough to wreck the magazine & blow it out of the gun, and probably the extractor off too.

If you are loading medium to light .40 S&W loads, the first sign of failure will be cracked case necks from too many firing, resizing, and expanding cycles.

And that is harmless if you catch it and don't load it again.

rc

243winxb
December 15, 2012, 04:01 PM
May depend on the type of frame, plastic or steel, in a 40 S&W. Steel being safer. IMO.

243winxb
December 15, 2012, 04:46 PM
Story & photos > http://www.thehighroad.org/showthread.php?t=646086 More photos > http://photobucket.com/KABOOOM

readyeddy
December 15, 2012, 06:33 PM
I use 10mm brass until I can see light through the walls when looking inside the brass. No disasters.

jmorris
December 15, 2012, 06:46 PM
Sometimes its no big deal just a split. Other times, like with a double charge, it can be, well catastrophic...

kingmt
December 15, 2012, 08:00 PM
RC did it well. I'd like to add if your cases don't bulge at the ramp you probably have no worries but if it does I wouldn't do more them a couple loadings because that is the failure that will blow out your mag & possibly your grips.

56hawk
December 15, 2012, 08:13 PM
Had what I guess you could call a case head failure with a 40 S&W. If you look at the picture you can see that it came off right at the extractor groove. Shot this out of a Beretta 96 and all it did was damage the extractor. I've shot tens of thousands of reloaded 40's and this is the only one I have ever seen do this.

http://www.thehighroad.org/attachment.php?attachmentid=153411&d=1322248317

GLOOB
December 15, 2012, 08:21 PM
In most rifles, the chamber is near completely closed until well after pressures have substantially subsided. I've experienced 9-10 casehead separations in my 223 rifle (OF'd internet brass, o boy!), and I didn't notice anything different until I pulled the trigger on the next shot and nothing happened, because the next round wouldn't chamber. Got to the point where I would automatically know what happened, clear the broken case head, rack in a round to extract the broken case, rack in a new round and keep going.

In most pistols, there's some unsupported area of the chamber where the brass can fail during peak pressure. In a plastic framed gun, this could blow the frame apart.

OTOH, the pressures can still be relatively high even when the action opens. As the case comes out, the pressures are lower, but more of the case becomes unsupported. This is how I suppose those 40 cases with guppie bellies that go more than halfway up the case are born. If the case blows out at this point, maybe nothing really bad happens.

Another thing that can happen with an overcharge is the case does not extract at all. The pressure is too high, so the case won't slide out of the chamber. The extractor slips off or tears through the rim, and then if pressures are still too high at that point, the case head can blow clear off like the cork out of a champagne bottle. So if you overcharge, you can have "catastrophic" brass failure even in a handgun with 100% casehead support.

45lcshooter
December 16, 2012, 12:19 AM
+1 for rcmodel and GLOOB!!

oldandslow
December 16, 2012, 04:08 AM
B25, 12/16/12

I've had one complete 9mm case separation and four partial case head ruptures after misreading the new powder max load when switching from Western 1420 powder to W231. I was loading 0.5 grains over max with the new W231 powder. The pistols used were a SW 3914, CZ 75 compact and a SW 5906. I kept the separated/ruptured cases as a reminder to read the powder load data more closely. With the partially ruptured case heads you get lots of powder and metal fragments blown into your face (a good reason to always wear eye protection). The complete case head rupture blew the left sided grip off the CZ-75 compact (I was shooting right handed only that time). I was using a mixture of manufacturer's cases and only the Winchester cases ruptured. The Federal would buldge but not rupture.

So the moral of the story is; pay attention to the reloading data, wear eye protection and avoid case head rupture/separation at all costs.

Merry Christmas- oldandslow

Grumulkin
December 16, 2012, 06:17 AM
You will not get a case head separation with straight-wall pistol brass.

The reason for case head separations is thinning of the brass above the web from cycles of shooting and resizing. When a case is fired we all know it expands and when resized the brass has to somewhere. That somewhere is toward the mouth of the case since the brass at the head is much thicker. That means that case head separations can happen in ANY type of cartridge whether straight walled or bottlenecked. Factors making head separations more likely include hot loads, sloppy chambers and case construction like tapered, thin or bottlenecked cases that makes brass more likely to stretch.

Straight walled cases don't stretch as much as bottlenecked cases and generally are used at much lower pressures so head separations in them usually never happen because other parts of the case fail first.

As for what happens when a case fails? In a strong action like a bolt action rifle not much. With a weaker action; I don't know but I presume the shooter or gun could be damaged.

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