Cracked shoulder

[boltfluter]

I have had new, just fired cases split like this, and never did figure out the cause....these are 6 mm ARC cases (necked down 6.5 Grendel) that I had formed and fired out of an ar. I formed and fired 50 cases, and these are the only 4 that split.(only 3 in pic)..other cases had no signs of stress or failure...the shooting gods have a weird sense of humor.....rsbhunter

I honestly believe that is a manufacturing defect from day one.

 

[bozo699]

The marks on the cases are a mystery ? But , aside from that, the cases just need to be retired. NOT to hijack your thread, but how many firings do you think a case is good for? What is the general consensus of firings a lapua case, pushed to normal full pressure loads, will last? I ask because I use Norma cases for my 6mm Norma Dasher rifles, and have 5-8 firings on those, and other calibers that use Lapua brass. rsbhunter

I’ve got over 30 firings on some of my 6brx cases. I retired them long ago for br competition but there still killing ground hogs.
Wayne

 

[Dusty Stevens]

Id bet 98% those marks on the case body are FOD in your chamber. Looks exactly like when i get a brush bristle in there- perfect negative impression. As far as the crack- ive seen them on first firing and when the brass is old. No rhyme or reason

 

[rocketron]

These are new out of the box br cases. I was told they are folds from when the brass was formed.

 

[bozo699]

Id bet 98% those marks on the case body are FOD in your chamber. Looks exactly like when i get a brush bristle in there- perfect negative impression. As far as the crack- ive seen them on first firing and when the brass is old. No rhyme or reason

Ditto!^^^^^^^^^
Wayne

 

[bozo699]

These are new out of the box br cases. I was told they are folds from when the brass was formed.View attachment 1330885

I’ve seen that before myself and they usually iron out when fired but will eventually fail in that area and it’s exactly what happened to the op more than likely
Wayne

 

[K22]

These are new out of the box br cases. I was told they are folds from when the brass was formed.View attachment 1330885

Cold laps (folds) and / or forming defects are quite common in many of the Winchester cases I purchased in the past. Anywhere from about 3 to 10 in a bag of 100 new cases. The 22 250 lots were the worse I encountered although I found them in 223, 243, and 308 lots also.

 

[darkangel_r2]

Check your die and chamber for any foreign debris. If you can't find any its probably a brass defect.

 

[rocketron]

I’ve seen that before myself and they usually iron out when fired but will eventually fail in that area and it’s exactly what happened to the op more than likely
Wayne

I never got that lucky they always split. I used them as set up for neck turn or the amp.

 

[V509]

Watching with interest
I have a 223wssm that will crack 6-8 out of 10. I have tried factory ammo, new brass, and brass I have run thru my Ken Light annealer

 

[Dave M.]

I have had new, just fired cases split like this, and never did figure out the cause....these are 6 mm ARC cases (necked down 6.5 Grendel) that I had formed and fired out of an ar. I formed and fired 50 cases, and these are the only 4 that split.(only 3 in pic)..other cases had no signs of stress or failure...the shooting gods have a weird sense of humor.....rsbhunter

These type of cracks are a clear sign the brass was sized way too much. The die doesn’t match the chamber well and the brass is undergoing extreme expansion in the chamber. I assume this is a factory chambering as opposed to a custom rifle, correct? Longitudinal cracks in the body are often the first sign of combining a hot load with brass that has been sized too much through the body.
Dave

 

[Bill K]

More than likely just a flaw/bad case or two. It happens with the best of them at times, for reasons unknown in the metal make up of brass, no matter the maker of it.

 

[lazyMlazyK]

These are new out of the box br cases. I was told they are folds from when the brass was formed.View attachment 1330885

I saw a bunch of folds in new Winchester .30-06 brass I bought a few years ago. 10-15% of the bag of 100 pieces I bought new had them, and I never loaded them up, assuming the folds would be a quick failure point or could cause an increase in pressure. Was my caution necessary or should I have loaded them?

 

[rsbhunter]

Dave M. These were brand new, unfired cases.....necked down only. Fired in a factory bbl. Plus, there was no sign of pressure in any of the cases, primers, even the "magnum" belt that happen on some factory brass that had been fired. The ARC is a different beast, like I said, my buddy has 2 different brand bbl's, and factory ammo of one load blows primer pockets every other shot or so.....but either way, it's a moot point, that gun is sold...rsbhunter

 

[Dave M.]

Dave M. These were brand new, unfired cases.....necked down only. Fired in a factory bbl. Plus, there was no sign of pressure in any of the cases, primers, even the "magnum" belt that happen on some factory brass that had been fired. The ARC is a different beast, like I said, my buddy has 2 different brand bbl's, and factory ammo of one load blows primer pockets every other shot or so.....but either way, it's a moot point, that gun is sold...rsbhunter

Shocking.

 

[rsbhunter]

Ditto

 

[Old Navy]

Dave your first photo looks like a few cases I had while fire forming 6 BRX cases. Down the road after 20 plus firings a got a few more. That was time to re-barrel anyway.

 

[Dave M.]

Dave your first photo looks like a few cases I had while fire forming 6 BRX cases. Down the road after 20 plus firings a got a few more. That was time to re-barrel anyway.

I had 13 firings on it so I guess it didn’t own me anything

 

[DocCarbon]

I had 13 firings on it so I guess it didn’t own me anything

Do You have a New case ,that you can do a detail photo on and then fire said case with follow up photos ?.

I'm Most curious as to what we may or may not find . I'll reserve comment until such time deemed appropriate .

 

[Dave M.]

Do You have a New case ,that you can do a detail photo on and then fire said case with follow up photos ?.

I'm Most curious as to what we may or may not find . I'll reserve comment until such time deemed appropriate .

I do but I don’t have any idea of what you are thinking so until I do, I’m not one for mystery testing. Care to elaborate??