.357 Magnum case failure

[gmerkt]

This was a new one for me. Complete circumferential separation. This was a GECO (Gustaf Genshow, made in Germany) case. Recently, I had about 50 such cases (nickel plated), about half of them split longitudinally while being resized. This was fired with a magnum load, but not at top end. 158 gr. jacketed bullet load 7.6 gr. Herco. I like Blue Dot better in .357 Magnum, but it's difficult if not impossible to find for sale now.

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[JRuby]

If they are splitting why did you continue to use them. After the second split case they get discarded or broke down. That's my thinking. Firearms are too exspensive to take the chance. Body parts don't grow back very well.

 

[Caveman Jim]

Never seen one separate like that.

 

[2Wheels4Ever]

I've had 4 or 5 do the same thing in my Rossi M92. However, the cases had been reloaded 8-10 times.

 

[po18guy]

Headspace issue? Cylinder end play issue? Crud in the forward section of the chamber?
I have nickel W-W .357 cases that have been carbide resized several times and I shoot max W-W 296.

 

[TTSX]

How neat. Looks like you found your case's limit on reloads. So just load them one less time and you're golden

 

[Member 361]

This was a new one for me. Complete circumferential separation. This was a GECO (Gustaf Genshow, made in Germany) case. Recently, I had about 50 such cases (nickel plated), about half of them split longitudinally while being resized. This was fired with a magnum load, but not at top end. 158 gr. jacketed bullet load 7.6 gr. Herco. I like Blue Dot better in .357 Magnum, but it's difficult if not impossible to find for sale now.

View attachment 1955156

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[po18guy]

How neat. Looks like you found your case's limit on reloads. So just load them one less time and you're golden

Universal torque rating for bolts: Tighten until the threads strip, then back off 1/4 turn.

 

[po18guy]

Headspace issue? Cylinder end play issue? Crud in the forward section of the chamber?
I have nickel W-W .357 cases that have been carbide resized several times and I shoot max W-W 296.

To expand on this, cylinder endshake "might" be an issue, if it allows the cases to set back more than design limits upon firing.
As to the chambers, crud in the chamber or rough chambers can cause the thinner, forward section of the case - which is forced outward gripping the cylinder walls - to hold tight during firing. Opposed to this, the unsupported case head is forced back from pressure opposite to the bullet. The peak stress between these two forces is basically where your case separated.

 

[DizzyJ]

Don't see THAT very often with a straight walled case!

 

[quneur]

Grind down the rim and you'll have .380 acp case.

 

[Nosferatu]

A strip a duct tape and you'll get a few more loadings out of it.

 

[gmerkt]

If they are splitting why did you continue to use them.

My post above might be confusing. Two issues going here. The unplated, brass case was part of one group. It was a single failure the split radially. The other issue concerned a different batch of GECO nickel plated cases. These were fine when fired. But when I resized them, that's when they split,cracked, not when they were fired. Which is another thing. But I'm not reusing any GECO cases.

Headspace issue? Cylinder end play issue? Crud in the forward section of the chamber?

None of the above. As old as it is, this revolver is fairly low round count. I think this one was just a fluke. It was the only case that split like this.

Looks like you found your case's limit on reloads.

I believe this one was on the third time around.