Can you guess what caused this failure?

[lancetkenyon]

Unless upon closing the bolt, the bullet slid back into the case

You still are not getting a .355" case neck (.325" bullet + .015" (x2 for .030") neck wall thickness) into a .342" (.308" bullet = .015" (x2 for .030") neck thickness + .004" clearance) chamber neck.
The bullet would have to slip all the way past the neck into the powder column for the neck to crush .013". I doubt anyone could close that bolt.

 

[xsn10s]

I don't think it is a case of "wrong diameter bullet", because you cannot close a bolt with a .325WSM carteidge in a .300WSM chamber. A .355" case neck will not go into the .342"(ish) chamber neck. Unless you are a gorilla with a sledge hammer.

Yeah I stand corrected. Looks like saami list od as .3580 for the 325 wsm and .344" for the 300 wsm. It probably wouldn't fit. Good catch Lance.

 

[xsn10s]

Only other thing I can think of is a double spike on the pressure.

 

[montana7mmhunter]

View attachment 283122

OMG!!!!!!!! Thank God for you lived to talk about it.

 

[dkfixer]

View attachment 283122

Looks like a lot of copper built up in the rifling

 

[Muddyboots]

I agree it's not much info and fairly vague. No proof of the source. But my point was the "Norma page" they fired somewhere near 200 rounds of a "7mm super magnum" to get to proof pressures. 300 wsm isn't near over bore as what the page described. So I inferred that this wasn't the issue.

Totally agree, my only thought of what caused it is an obstruction, of which we will never likely know. I am though, intrigued over how a barrel can be copper smeared like that.

 

[Treeslug]

Carbon Ring, I saw it right off

What did you say, Butter Bean? I couldn't see your lips moving for all the carbon in my eyes, and everybody knows I cain't hear nothin'.

 

[Barrelnut]

Those are some DEEP flutes on that barrel. It did split along the flutes. Looks like the ultralite craze gone too far. Not saying they caused it, but surely didn't help.

 

[VTbluegrass]

Did the guys on one of the gun shows do this to guns in the torture test?! That's an obstructed barrel. Are you missing a laser boresighter perhaps?

 

[Blackhawk]

I'm sorry that this had to happen to you.
However it serves as a reminder to all of us who reload to be very diligent while we reload.
It could have been caused from a myriad of issiues that may or may not have been covered.
I'm just glad that you were not injured !

 

[xsn10s]

Totally agree, my only thought of what caused it is an obstruction, of which we will never likely know. I am though, intrigued over how a barrel can be copper smeared like that.

Some of the mono's will do that when a different jacket material was in the bore. I've seen AccuBonds foul badly too for the same reason. Over pressure rounds would be operating at a higher temp too is my guess. Causing the bullet to shed more material. Anybody's best guess.

 

[Fedwell]

Ask JoeBiden he will know?

Sleepy Joe thinks COVID did it

 

[Treeslug]

Sleepy Joe thinks COVID did it

You are going to have to ask Doctor Jill for a correct and complete diagnosis.

 

[Carlos88]

Here are two photos of a 7WSM barrel that was fired with the laser bore sighter left in the barrel. Model 70 this was the first round this rifle ever fired by the owner.

Man that would make a great lamp. Expensive but still great.