Kaboom 💥 Today 😟

[DoneNOut]

I would say bad brass too. You can see the separation line goes all the way around.

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What brand? And how many pieces?

I think I would ditch them all if it were me. Start over with new brass.

This was once fired Lapua brass.

 

[243winxb]

1x fired 708AI brass

What case was used to fireform, 7mm-08 or 308 win? To much case stretch on the first firing can damage brass & cause case head separations, later.

edit this- **For the case head to be gone, very high pressure may be the cause.**When necking down brass, the loaded rounds neck diameter need to fit the chamber. If to large, the bullet gets crimped in tne case = Kaboom. Hard bolt closing would be a sign.

The clean cut is a little puzzling. To perfect. Two things come to mind.
The gap between bolt & barrel face may be excessibe. More then .010" What action are you shooting?
Some brass is manufacfured in 2 pieces, then formed. The case head is stamped & swaged to the case body, under very high pressure.

I can guess, but at times, we may never know the cause.
https://www.thehighroad.org/index.php?media/albums/kaboom.24/

 

[trout004]

I'm only .0015 shoulder bump. Other fired cases look fine. I'm probably at 200rnds through the barrel.

L

What case was used to fireform, 7mm-08 or 308 win? To much case stretch on the first firing can damage brass & cause case head separations, later.

For the case head to be gone, very high pressure may be the cause. When necking down brass, the loaded rounds neck diameter need to fit the chamber. If to large, the bullet gets crimped in tne case = Kaboom. Hard bolt closing would be a sign.

The clean cut is a little puzzling. To perfect. Two things come to mind.
The gap between bolt & barrel face may be excessibe. More then .010" What action are you shooting?
Some brass is manufacfured in 2 pieces, then formed. The case head is stamped & swaged to the case body, under very high pressure.

I can guess, but at times, we may never know the cause.
https://www.thehighroad.org/index.php?media/albums/kaboom.24/

With this in mind, if headspace/shoulder setback has been confirmed, maybe cut a case in half to examine the head thickness at the stretch point and examine for stress marks?

 

[hardluck]

Dadgum!

 

[SSG Graybush]

I'm only .0015 shoulder bump. Other fired cases look fine. I'm probably at 200rnds through the barrel.

Then I'd be calling Lapua.
Curious what powder and charge weight? Maybe pull the rest and check charges too.

 

[cohunt]

Maybe I'm missing somethin-- you said 7-08ai lapua brass-- you said 1x fired with 1.5 thou shoulder bump-- lapua doesn't have 7-08ai brass, just std 7-08 so you've fire formed it. Is this a true ai chamber with just a slight shoulder crush fit? Or possibly a longer chamber that uses a bullet jam?

What was your forming process and load? What was your 2x firing load? Speeds?
Tell us more info, and what rifle?

 

[Old Rooster]

Scary brother!
Glad you still have all fingers.

 

[akdad]

Glad your ok!

 

[victor3ranger]

Things shooting good with 1x fired 708AI brass. (Lapua) 12th round shot and gun explodes out the mag well, ruptures mag and extractor. Ruptured case easily fell out the chamber. The separation line looks too clean. Bad brass? 11 fired cases look fine. No serious pressure signs.
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Wow
That's a super clean break, never seen anything like that

 

[Hand Skills]

Agree, *way* too clean.

I hope Lapua follows up with you @Gingerman,

Very curious as to what their response response will be.

Glad you are OK man,

Between WLR primers etching your boltface, a broken press, and now this... Well, if bad luck comes in 3's, hoping you are now in the clear!

 

[jessej]

Like many here, I've been loading over 50 years, with many wildcats. Never seen that?

A few less years but otherwise the same here.

 

[Panhandlin Pat]

I've had plenty of case head separations, even to the extent of having to dig the front half out of the chamber. All from rear locking lever guns (savage 99, mossberg 30-30). Never seen the base blow like that. Pretty spooky

 

[436]

Clarification, when you say; "No serious pressure signs" are you eluding to there was pressure, but... it didn't seem serious? I'm just trying to read between the lines. Glad to see you came out the other side on top of it... that sure could have turned out much differently for sure. Cheers

 

[Calvin45]

Well that's terrifying. If your eyes and hands are fine I say go buy a lottery ticket now.

This is truly weird. I wanna ask if there's any chance whatsoever that something about that cartridge was waaaaay different (as in grossly heavier powder charge, a different heavier projectile somehow got in with what you were loading, etc…) but even if it was a wildly overpressure round absolutely nothing about the MANNER of this case fail makes any sense to me. It's not that it failed. It's that it failed LIKE THIS and what it looks like now.

I'm guessing there was something very very defective with that piece of brass to begin with.