Split case

birddog 68

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This is a first for me. I've had split neck's before but never on the body.
I worked up to pressure and then backed off a full grain which is how I normally do it. Next outing on the third shot this happened. Everything looks fine on the other cases, no pressure signs.
I'm thinking that there was some type of inclusion or the wall has just thinned too much from full length sizing but I'd like to hear what others think.
280 AI, Nosler brass on 5th firing. Was annealed after 3rd firing and primer pockets are still tight. 60 grains of IMR 4350 (.5 grain under book max) using 120 grain ballistic tip.
76416B47-692D-4672-90A9-447EB8F930B9.jpeg
 
Maybe its the picture but the case looks bulged above case web on the right. A well known barrel maker over polished my 280ai chamber and polished it heavy on one side and created a .010 bulge when fired. They wanted me to keep the barrel but i shipped it back for a new one. Also, keep in mind that you can easily be operating well over rated pressure without pressure signs.
Have you measure the fired brass and compared to chamber specs?
 
Why does that case look so tarnished? It looks like an old military round. Maybe it's just the image. ???

I'd be inclined to send that image to Nosler for their opinion before using more brass from the lot.
 
Why does that case look so tarnished? It looks like an old military round. Maybe it's just the image. ???

I'd be inclined to send that image to Nosler for their opinion before using more brass from the lot.
I think the tarnished look is from when everything leaked out when fired. I'm not a habitual case cleaner though. lol
 
I think I see the problem 🤔
There is a crack in it.
Just kidding, I have never seen rifle brass crack length wise before. I have seen pistol brass do that when the case mouth was crimped on 10mm and the case was pushed into the barrel chamber rupturing the brass.
Like you said maybe wall thickness was uneven. But seems to me it would have to have an obstruction for the gasses to blow out like that. But I don't know besides cutting open the case and measuring.
 
What brand? That happened to about every six cases when I loaded new Ammo, Inc brass for my .223 (for PDs, I just wanted the cheapest brass; turned out to be expensive).

Wait, I see...Nosler brass. I know it gets a bad rap, but Nosler has worked well for me (though it isn't a favorite).
 
I think I see the problem 🤔
There is a crack in it.
Just kidding, I have never seen rifle brass crack length wise before. I have seen pistol brass do that when the case mouth was crimped on 10mm and the case was pushed into the barrel chamber rupturing the brass.
Like you said maybe wall thickness was uneven. But seems to me it would have to have an obstruction for the gasses to blow out like that. But I don't know besides cutting open the case and measuring.
I had a 257 roberts case split that way 1 time while fire forming to 257 AI
 
What brand? That happened to about every six cases when I loaded new Ammo, Inc brass for my .223 (for PDs, I just wanted the cheapest brass; turned out to be expensive).

Wait, I see...Nosler brass. I know it gets a bad rap, but Nosler has worked well for me (though it isn't a favorite).
Yes it's Nosler. It's what was available at the time and definitely isn't top shelf brass but it's been serving it's purpose, until now anyway.
 
I think I see the problem 🤔
There is a crack in it.
Just kidding, I have never seen rifle brass crack length wise before. I have seen pistol brass do that when the case mouth was crimped on 10mm and the case was pushed into the barrel chamber rupturing the brass.
Like you said maybe wall thickness was uneven. But seems to me it would have to have an obstruction for the gasses to blow out like that. But I don't know besides cutting open the case and measuring.
Definitely no obstruction and loaded .050 off the lands.
 
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