My first Case Separation/Broken in half.. Safety and Out of the fight ideas

[John Gault]

Here's a picture of a 300 blackout case that recently broke in half on firing. The case was a modified Nato 5.56 that I purchased as complete ready to load. Loaded by myself on progressive press using the H110 powder that I'd been complaining about metering issues. This was supposed to be an 18.5 grain load on a 110 grain Zmax bullet.

Not sure if it was an over load on the powder or a bad casing to begin with or fired prior to full seating or?? Needless to say I'm going to pull down the last 10 of these unfired and check powder load consistency.

Any ideas are welcomed..
The upper half of the case was in the and the back half got stuck on top of the carrier above the next incoming round. Took me out of any chances of fighting if it had been required. The front half of the casing was not visible to me initially I only assumed that it was in the ..... What would have happened had i tried to load another round?

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[rick benjamin]

Excessive pressure
flattened primer
ejector mark next to the "4" on the head

 

[ma96782]

I would figure....that maybe the brass was old and it was just it's time. If it were to happen a lot....I might be more concerned.

Huh?

OK (story time)......

I shoot my .308 Win reloads made with LC brass out of an M1A. When I see the signs of a separation, the entire lot gets dumped. Sometimes I can get 4 reloads out of a lot. Yes, I've had my reloaded brass separate (just like yours) and it's no fun. Thus, trying to be diligent is about the best I can do. LOL, my brass was probably shot out of a M60. Yup...the brass is that old and back then, M60s were known to have generous chambers. Besides....an M1A isn't exactly a tightly chambered bolt action either. So, looong brass life isn't really to be expected.

Anyway.....

So, maybe your once fired brass might have been fired out of a "slightly generous chamber." Full auto or semi auto........fired out of a M16/M4 and/or M249. It's used/fired brass. It doesn't matter, the used brass all get's thrown into a recovery bin. Later, it's sold off to the highest bidder. Yup, the processer will take his bin of used brass and just process it. And, you bought some. Mind you........buying used brass/processed brass, is NOT always a bad thing.

Then....

Yes, over loading a cartridge case w/ gun powder could also do it. But, how much powder did you actually use?

When I once loaded IMR3031 into a .223 case I also had "problems." I didn't feel all that comfortable when stroking that powder measure handle and feeling it "cut" the powder stalks. Humm.....stick powder. Not to mention, the volume of space that was taken up.

After I switched to a ball powder....I was much more comfortable. And volumes in the cases were looking much better.

Anyway...

There is also your reloading technique. Do you gauge your reloads?

And, what about your rifle's chamber? Is your chamber generous?

Humm......there are many things to consider.

Aloha, Mark

PS....the trainers at the Police Academy told us that ammo only needs to be fired ONCE. Reloads were for practice.

 

[v0lcom13sn0w]

to me, that primer aint flattened so i wouldnt call it excess pressure.


it seems like a pretty clean split. maybe the case was heated up or somethin during the 5.56- 300blk conversion and had a weak spot??? i dont know.

 

[Member 5605]

Brass had been fired too many times and resized..? Your once could be somebody else's 4x and left on a range.

I check my brass:
Instagram video by T. King • Jul 8, 2016 at 12:42am UTC

That thin spot is a biotch. My brass. The separation caused the head to slam the bolt face, flattening the primer and etching the extractor mark on the brass. It sucked and I learned.



Google image:

 

[ma96782]

Oh yes.....

Heating it up....maybe during annealing?

Aloha, Mark

 

[v0lcom13sn0w]

Brass had been fired too many times and resized..

I check my brass:
Instagram video by T. King • Jul 8, 2016 at 12:42am UTC

That thin spot is a biotch:
View attachment 310615 View attachment 310616


Google image:
View attachment 310617

dude, ive been loading for 5-6 years... reading some of your threads and posts ive come to the conclusion that youre a reloading guru. i swear it.

im not kidding.

 

[Member 5605]

dude, ive been loading for 5-6 years... reading some of your threads and posts ive come to the conclusion that youre a reloading guru. i swear it.

im not kidding.

Haha, nope. Not a guru. I've just screwed up enough times. We sir have been reloading the same amount of years.

 

[v0lcom13sn0w]

Haha, nope. Not a guru. I've just screwed up enough times. We sir have been reloading the same amount of years.

ive never made some bench rest accurate loads like you have. but, i have worked up some pretty nasty 308 loads for hunting! usually, i bang out my handgun rounds 1k at a time.my 5.56 1k at a time. all single stage on a rcbs jr2( i do one stage at a time so i dont get burnt out, one night for a few hrs i'll size/deprime 500-1000 cases and the next time i go out i'll do the next step and so on...). my 308, '06 and 300WM however, i do 1 at a time, trickling the very last .1 grain onto the scale. its really satisfying harvesting a big game animal with a round i have made. not to mention, all the hard work thats already involved with taking an animal, this just adds to the excitement!

 

[AMProducts]

So the process by which case head separation happens is typically at a transition point where the hardness gradient of the brass changes from the soft springy part (necessary to seal the chamber) to the harder head section.

What happens over-time is as the front part of the brass work hardens this section of the brass doesn't work harden as much, this causes increasing levels of fatigue as the brass is used. Over time, this hard condition can lead to age cracking. Typically this would be seen first on the case neck, unless you annealed your brass, which would make the case head separation a much more common failure.

From what I've seen, I don't see any signs of increased pressure that might have caused this failure, in fact I consider that to be extremely unlikely mainly because when you're dealing with over-pressured cases that have ruptured you see a blown primer, and much more deformation of the case.

The .300BLK cuts off a good chunk of the neck of the case, using a much harder piece of the brass


This is the hardness gradient of .223 ammunition after the scamp and case neck anneal process. the two lines are where the hardness must be between.

As you can see, the peak hardness is right about the .7" mark, and then drops off quickly after that. I don't remember what the trim length is on .300BLK, but you can see the gradient is going to be harder (albeit not significantly) than .223, but it could explain why this is where the failures occurred.

Generally speaking, if you want peak reliability for defensive ammo, either buy new ammo, or buy new components. Save the reloads for range day.

 

[Certaindeaf]

Yea, the next best is "once fired" and the only way to know that is to have fired them once yourself or they have factory crimped primers still in them.
Anything else is suspect and you're just hoping that they are.

 

[ron]

A issue my buddy ran into with 223 range brass.He had a similar separation
as yours. Sent the case to an expert. The conclusion was the brass was
cleaned with an ammonia product? Used brass picked up at a gun show.
I have loaded 10's of thousands of 223s, 30/06 and 308. I have never had a case separation. Maybe just lucky? I now carry broken shell extractor for each caliber
in my range bag.

 

[Velzey]

Pretty common when dealing with all types of range brass. Well I should say common bad luck for me I swear if there is bad brass I will find it. Bad thing is a stuck case remover sometimes doesn't work well when there is a midcase separation.
Large belted mags seperate about an 1/8" forward of the belt. Case remover works great for that.

I have had brand new 30-06 brass fail, and brand new military rounds fail. And a midcase separation put a 2 day break in an awesome hunt a few years ago. While I drove home to retrieved another rifle. Thankfully my first shot killed the muley but it sounded funny and some smoke came out of the vent hole in the side of my rifle. Uh oh and it was brand spanking new ammunition.

 

[AMProducts]

There are two ways to remove a broken shell... The first way is to use a cleaning rod with an oversized brush, this usually gets them out. The more complicated way (if the first way doesn't work) is to use a cleaner that contains ammonia, I typically use Sweets 7.62 for this (because that's what I clean my rifle with anyways). Get a patch sloppy wet with the stuff, and stick it in from the breach end, and slather it around in there. If possible set it in the sun on a flat surface (so the stuff doesn't run out). and wait, usually within a few hours it'll corrode the brass enough that you can get it out using the cleaning rod.

If that doesn't work, you can use ammonia dope, but that's more involved still, and requires filling the bore with the stuff, and setting it on end, and waiting for the brass to completely disintegrate.

You can also use mercury that readily forms amalgams, but that's toxic and a massive pain in the butt, and realistically ammonia works better on copper alloys anyways.

If you do have a broken shell extractor, they do work, but are sometimes difficult to use. The easiest way to make sure it's properly jammed in there is to put in the extractor, close the bolt on it, and then if you have a cleaning-rod attachment that's got a flat-tip screwdriver, tighten up the screw in the end. Try not to over-do it.

 

[John Gault]

Thanks everybody for input. I found another case that I fired that has a micro crack in the same location. Starting to sift thru the remainder of brass I purchased to look for anything obvious.

I'll probaby buy some new brass for my serious loading and consider 1x 300 blackout brass for everyday use and leave the 5.56 conversion for worst case senerio times. The reprocessed brass bought was not annealed post processing from appearances.
I was able to get my stuck casing out with a cleaning brush very easily thank goodness. Fortunately someone else had one as I was only there to put a few down range and didn't bring anything with.. Considered banging the butt stock on a bench with barrel pointed in air as I might have to in a SHTF senerio but it's a brand new and expensive toy...

 

[Velzey]

There are two ways to remove a broken shell... .

Well there is another sure fire way but I do it as a last resort. even if the case head is still intact. If its just a case separation I plug the bore and fill the chamber with cerrosafe. I then use a long brass rod, and use a heat gun on the chamber. Heat the chamber just until its to hot to touch with your fingers, and tap on the brass rod.
If the case head is still intact I plug the bore, drill a hole in the head and pour in cerrosafe. Once again heat the chamber area with a heat gun and then use the brass rod. tap tap tap and out come the stuck case.

The main thing is when your using cerrosafe is that you don't use to much. I once slipped when pouring it into a chamber of a Ruger number 1. That stuff went down into the lockwork... took m ehours to pick it all out with dental picks..But no harm done.

 

[AMProducts]

Thanks everybody for input. I found another case that I fired that has a micro crack in the same location. Starting to sift thru the remainder of brass I purchased to look for anything obvious.

I'll probaby buy some new brass for my serious loading and consider 1x 300 blackout brass for everyday use and leave the 5.56 conversion for worst case senerio times. The reprocessed brass bought was not annealed post processing from appearances.
I was able to get my stuck casing out with a cleaning brush very easily thank goodness. Fortunately someone else had one as I was only there to put a few down range and didn't bring anything with.. Considered banging the butt stock on a bench with barrel pointed in air as I might have to in a SHTF senerio but it's a brand new and expensive toy...

For a while Armscorp was making 300BLK that was available domestically. Look around and see if you can find yourself some of that for your "SHTF" supply. Load it up and sit on it. Even then, I regularly see 300blk at walmart, buy a few boxes every week or two before long you'll have a lot of ammo.

Shoot the conversion brass... it's cheap, and available in large quantities. If you're stuck PM me, I have a ton of it.

 

[Provincial]

I once removed a broken case from a .303 SMLE by using a tap. I screwed the tap into the case from the chamber end, and only gave it about 1/8 of a turn. I then applied pressure with a cleaning rod from the muzzle and it came right out.

You want to be careful not to cut through the brass case and damage the chamber. It doesn't take much to get a grip on the inside of the case with the tapered part of the tap. With bottleneck cases, there are several points the tap can grab.