Case head Seperation

[phatfarmerbob]

Sauer model 200 chambered in 270.

Possible case head separation.

Reloads were my grandfathers as it was his, it’s been a safe queen until today. First two shots were fine then third shot and mag blows apart and out the bottom. Attached are pics, couldn’t even find mag spring and I really looked.
All I can say is eyes and ears kids it only takes a second.

 

[HighlandLofts]

That was a LOT of pressure. I'm glad no one was injured, could of be catastrophic. It only takes a split second.
I'm sure the guys will chime in on the reason, I have no idea.

 

[Shoots100]

It looks like there's some old over worked brass in the mix to me, as some of the necks are turned and those have probably been resized and loaded more than the others.
In what I can see of the primer on the blown case, it doesn't look flattened or blown out, so pressure couldn't have been that bad.
If possible, you should pull the bullets from the cases with the turned necks and check the brass for hairline cracks on the inside with a dental pick.
SJC

 

[Mosinitis]

Pressure problem that separated the case plus other things. It's not case separation that caused this. Case separation here is the effect, not the cause.

 

[kev74]

Pressure problem that separated the case plus other things. It's not case separation that caused this. Case separation here is the effect, not the cause.

I agree.

I've had cases let go that didn't blow out a magazine. If I were to guess, I'd say either overcharge or wrong and/or contaminated powder.

In any case, I woudn't shoot any more of the reloads. Pull the bullets, dump and replace the powder with fresh accurately measured powder and reseat the bullets.

 

[phatfarmerbob]

Looks like max load is 54 gr this was 51.3 this is disappointing. Those three shots were .75 MOA I know I could rope it in even more. Also looks like mags are wicked pricey. Mehhh

 

[Shoots100]

Pressure problem that separated the case plus other things. It's not case separation that caused this. Case separation here is the effect, not the cause.

If there were signs of overpressure, I would agree, but look at the primer.It's not even close to being flattened and no sign of any blow back on the neck, or marks from a hard extraction from an over pressure issue.
Case separation is the effect caused by thin overworked, or oversized brass.

 

[phatfarmerbob]

Bolt gun , no extraction issues with bad case...

 

[Shoots100]

If you have the equipment and good brass to reload for this rifle, I would check the sizing die before loading.
Back the die out a turn or two, size and chamber check the brass till the brass chambers in the rifle, then lock the die down.
Load away and check back in to let us know how you made out.
SJC

 

[Acer-m14]

could have been a cracked case grandpa missed in sorting and loaded it .. hard to say why .. without before pics of the round ..
I would check all his reloads for cracks and blemishes and measurements or just disassemble them and reuse what is good ..

 

[Mosinitis]

If there were signs of overpressure, I would agree, but look at the primer.It's not even close to being flattened and no sign of any blow back on the neck, or marks from a hard extraction from an over pressure issue.
Case separation is the effect caused by thin overworked, or oversized brass.

Case separation occurs higher where case walls are thinner. This looks like the case ripped at unsupported perimeter between bolt and chamber. It looks like the primer was pierced as well. The worst of case separation I seen was upper half of the case stuck in the chamber, no damage of any kind.

 

[Mosinitis]

I wouldn't shoot anything through my rifle which wasn't reloaded by me, much less if the rounds are blowing up. Destroy that ammo, don't give it to anyone. A number of possible problems could have caused this. It's just not worth the risk and time to pinpoint the problem.

 

[phatfarmerbob]

This is awesome, this model is discontinued and there are no magizines in the us. I’m gonna take it up the ass if I find one in Europe and have to get it shipped

 

[dsdmmat]

take the parts to someone who can 3d print. The spring replacement can be hand made.

 

[Deplorable Me]

How old was the brass? Any idea how many reloads? Did reload data come from an older manual?

A friend pointed out that older reload books provided data for hotter loads, current books have backed off on max load for liability issues. Also, if the brass was ever exposed to ammonia or an ammonia atmosphere, the ammonia reacts with the brass and makes it brittle. Brass polish for non-reloading purposes has ammonia in it (Brass0). I've seen warnings about NOT using it.

In my shop I have a little wire probe. Basically steel wire about 4" long with a 1/8" "L" on the end. I run it into the case mouth down to the case head end. You can feel a bump inside the case if the case head is thinning.

I only load maximum reload charges for brass that has been shot once. Everything else I stay less than 80% for range-practice rounds.