Split case on factory ammo. What next?

[Norrick]

I have a friendly competition coming up later this month and I didn't have time to dial in a particular handload with my current supplies, so I just ended up buying a few boxes of Hornady Match ammo.


I was sighting in at the range today, it was pretty uneventful at first. Two shots one hole at 50. Move it out to 100, still tight but starting to spread. Maybe it was me, but I call this rifle the laser for a reason.

The 9th shot was louder and recoiled more than the rest. It felt like someone sling shot sand into my face. No lasting pain, just more startled than anything else (had safety squints on). This is what came out of the chamber.


I've never had a case split on me before, but I certainly expected the first time it happened to be one of my own loads, not factory ammo. So now I'm kinda wondering what next. Is there any risk to damage to my rifle?

The split case was the last round I fired. I packed up and left. Looking down with a flashlight, I can see the same long mark down the length of the chamber. But aside from that, I'm not sure what I'd be looking for.

Some other questions:

• I don't feel comfortable firing the rest of this box, but what about the other two boxes. If the lots are not sequential should I consider them safe?
• Is hornady generally willing to reimburse people for their troubles, or should I be dealing with the gun store (Bass Pro) ?

 

[Norrick]

EDIT: Rifle is Kimber 84m Open Country in .308 Win

 

[taliv]

that rim looks really jacked up. was it somehow fired out of battery?

 

[Norrick]

I'm not sure if that's possible, as its basically a mauser action. Bolt went down like normal, round came out like normal. No sticking or extra effort.

 

[troy fairweather]

normally when u split a case there is less recoil. unless there was a over charge of powder i could be just that hdy messed up the brass aneling and made it to hard. i would call hornady and just tell them what happened. id like to see the primer. did it blow it out ?. does not look like high presser tho the shoulder is not real sharp like with high psi and dont look like much bodge on the head of the case. if u can way all the ammo let just to see if there is any big difference like 5 or more grains off from the others. and check to that u did not goose egg the chamber to.

 

[Norrick]

I think the rim is normal (just discolored).


Primer also looks normal.


Will see if there's any noticeable difference in weights with the scale later.

 

[troy fairweather]

I think the rim is normal (just discolored).
View attachment 796710

Primer also looks normal.
View attachment 796711

Will see if there's any noticeable difference in weights with the scale later.

ya thinking the brass was to hard. still worth a call to hdy just to check.

 

[Venom007]

Call hdy and let them know and us too what they say

 

[Eugen]

OP, hats off to you for handling a horrifying experience very carefully and objectively. Hopefully your inquiry with Hornady will result in helpful answers to many questions.
We all await an update.

 

[Hokie_PhD]

I’m with the others.
Way to stay calm and logical.

I agree call Hornaday and please let us know.
I’m not an expert but my first thought was overcharge. But we all know it could be anything.

Hopefully they’ll make good, have you send the rest back and issue a recall if necessary.

 

[taliv]

hmm... maybe it's just me. the rim looked really distorted in that one pic. from the other views, i'd guess the only problem is a defect in the brass. stuff happens.

 

[someguy2800]

I would guess a brass defect also

 

[Jim Watson]

In mil-spec that is a K split and is a Critical Defect.
Contact Hornady, they should replace any you have of the same lot number.

 

[Slamfire]

You are lucky that you were using a modern rifle. Gas release into the action is very serious, dangerous on older actions.

The case is a gas seal, it is not a structural element, it is a gas seal, just like a cylinder head gasket. If a cylinder head or engine block warps, the gasket will rupture because it has to be supported. Similarly, the case has to be supported by the action and the chamber. The strongest part of the case is the case head, and by the nature of a repeating rifle, some of it has to stick out of the chamber, or you would have to extract the thing with a ram rod. Good designs, and the M1903 is not a good design, support as much of the case head as possible.



The case is slightly deeper in a M98 action, and I consider the M98 a good action.



Mike Walker made a very safe and strong action by surrounding the case head completely with the bolt face, barrel hood, and receiver ring. M700 actions have held together under pressure conditions that would have blown the receiver rings of lesser actions.



You can look at Merle (Mike) Walker's breech patent 2,585,195 here

https://patentimages.storage.googleapis.com/13/0d/a7/78b0fd99467aad/US2585195.pdf

If too much of the case head is outside the chamber, the sidewalls will rupture and then what happens afterwards is very unpredictable. It is well worth reading Vol IV of the Machine Gun by Chin. This series is free on the web and explains how important case support is to the design of weapons. These are pictures from the book:





A brass flaw in the case head, such as occurred in the upper cartridge, can blow an action, because the hole in the lower cartridge was in the chamber, probably nothing happened.



Older actions, made from plain carbon steels, either pre vacuum tube era technology, or even after, many of them will fracture due to the load of the gas from a case head failure. I don't know what lead up to the failure of this Swedish action, but it is evident that the receiver ring failed.









This M70 is made from modern materials and it is evident that the case head failed, causes unknown, but the action held, and if memory is correct, was still usable. A bud of mine fired a 270 Win cartridge in his belted magnum M70, the description of the rifle sounded similiar to these pictures, the scope and stock were blown all to hell, he got lots of brass and powder in his face, but the action was usable. Remember, always wear your shooting glasses!

Is there any risk to damage to my rifle?

As long as your case head failure did not blow the receiver ring, caused recession of the bolt lugs or receiver seats (very unlikely), did not cause erosion, like a gas etch, then your action is fine. High pressure escaping gases can blast off a firing pin tip, create an etch mark in the chamber, or someplace else, and depending on where the material was removed, could be a problem, may not be a problem. But if your rifle stays within factory headspace tolerances, then all you got was a face full of gas. I would remove the firing pin assembly and clean out the insides of the bolt, the thing is probably filled with powder residue.

Do remember, always wear your shooting glasses!

 

[troy fairweather]

You are lucky that you were using a modern rifle. Gas release into the action is very serious, dangerous on older actions.

The case is a gas seal, it is not a structural element, it is a gas seal, just like a cylinder head gasket. If a cylinder head or engine block warps, the gasket will rupture because it has to be supported. Similarly, the case has to be supported by the action and the chamber. The strongest part of the case is the case head, and by the nature of a repeating rifle, some of it has to stick out of the chamber, or you would have to extract the thing with a ram rod. Good designs, and the M1903 is not a good design, support as much of the case head as possible.

View attachment 796726

The case is slightly deeper in a M98 action, and I consider the M98 a good action.

View attachment 796727

Mike Walker made a very safe and strong action by surrounding the case head completely with the bolt face, barrel hood, and receiver ring. M700 actions have held together under pressure conditions that would have blown the receiver rings of lesser actions.

View attachment 796728

You can look at Merle (Mike) Walker's breech patent 2,585,195 here

https://patentimages.storage.googleapis.com/13/0d/a7/78b0fd99467aad/US2585195.pdf

If too much of the case head is outside the chamber, the sidewalls will rupture and then what happens afterwards is very unpredictable. It is well worth reading Vol IV of the Machine Gun by Chin. This series is free on the web and explains how important case support is to the design of weapons. These are pictures from the book:

View attachment 796729

View attachment 796730

A brass flaw in the case head, such as occurred in the upper cartridge, can blow an action, because the hole in the lower cartridge was in the chamber, probably nothing happened.

View attachment 796731

Older actions, made from plain carbon steels, either pre vacuum tube era technology, or even after, many of them will fracture due to the load of the gas from a case head failure. I don't know what lead up to the failure of this Swedish action, but it is evident that the receiver ring failed.

View attachment 796732

View attachment 796733

View attachment 796734

View attachment 796735

This M70 is made from modern materials and it is evident that the case head failed, causes unknown, but the action held, and if memory is correct, was still usable. A bud of mine fired a 270 Win cartridge in his belted magnum M70, the description of the rifle sounded similiar to these pictures, the scope and stock were blown all to hell, he got lots of brass and powder in his face, but the action was usable. Remember, always wear your shooting glasses!

View attachment 796736

View attachment 796737

View attachment 796738

View attachment 796739



As long as your case head failure did not blow the receiver ring, caused recession of the bolt lugs or receiver seats (very unlikely), did not cause erosion, like a gas etch, then your action is fine. High pressure escaping gases can blast off a firing pin tip, create an etch mark in the chamber, or someplace else, and depending on where the material was removed, could be a problem, may not be a problem. But if your rifle stays within factory headspace tolerances, then all you got was a face full of gas. I would remove the firing pin assembly and clean out the insides of the bolt, the thing is probably filled with powder residue.

Do remember, always wear your shooting glasses!

nice post hard to look at the lower part

 

[Jim Watson]

A brass flaw in the case head, such as occurred in the upper cartridge, can blow an action, because the hole in the lower cartridge was in the chamber, probably nothing happened.

The top case is an L or M split, depending on whether it reached the primer pocket or not.
ONE such would lead to condemnation of an entire production lot of ammo by the Army.

 

[Dr T]

Very informative. The M70 photos sort of make you understand why the warranty is invalidated if handloads are fired...

 

[fpgt72]

Very informative. The M70 photos sort of make you understand why the warranty is invalidated if handloads are fired...

Because like in the original post nothing can go wrong with factory loads.

 

[243winxb]

Is there any risk to damage to my rifle?

Very little risk of damage, as i see it.
If the pressure exited from a small hole, there may be a possibility of some gas cutting in the chamber, but looks like that did not happen.

If the ruptured fired case extracted with normal bolt lift, there was no overload.

The primer looks normal, no pressure sign.

1 bad piece of brass is my guess, but the rest of that lot would go back to Hornady , it it were mine.

 

[Bushpilot]

Can you feel any bulges in the case just above the case web on the other cases that you have fired?

 

[Picher]

Did you check the bore to see if there are any bulges, perhaps from foreign matter in it when fired? If not, try ammo from another maker or handload that you know is safe in that rifle. If it fires normally, it's probably the ammo.

 

[carbine85]

I'll throw dart here. I'm thinking a faulty case. The primers don't show any pressure problems.
Do the other cases show anything?

 

[792mauser]

There's a reason I love me a 98 mauser.
Busted the extractor and that was about it.
Got a face full of gas but not much else.

I'd say a bad case as well

 

[Norrick]

Got around to cleaning the rifle and taking some photos today.

Here you can see the gas mark corresponding to the case rupture at the 10 o clock position.


After cleaning most of it wiped away, except for the point of failure at the base of the case. If this is etched into the chamber, should I worry about it? The "scratches" are fibers from the cleaning patches.


Does anyone have any input on the hole in the 6 o clock position? I don't remember if it was there before the incident. It looks like it could be a slot machined into the underside for indexing or something else, but just seems out of place to me.

 

[troy fairweather]

should be fine. maybe try a shotgun brush in the chamber on a drill slow. the hole looks like the end of the tread on the barrel shank is my guess.