Broken neck

[caribouhunter]

This pic have been posted on a forum for some time
and nobody seems able to answer him so i thought
i'd post it here for him. I'm pretty sure some of you
Will know what can cause this.
Caliber is 300 wsm
he used once fired brass ( he bought them so are they really
only fired once?)


IMG_0037.JPG
thanks guys
i'll tranlate your answers and where i got the answers and from
whom it came to this Guy on the french forum.

Ex. Answer from caribouhunter on the nosler reloading forum
unless you specify otherwise for wathever reasons

 

[caribouhunter]

Pic doesn't work sorry
but it's a case broken just above the shoulder
the entire neck stayed in the chamber
but came out easily

 

[JD338]

I'm guessing a bad piece of brass.

What make brass and what was the load?

JD338

 

[FOTIS]

Send me the picture or link I will post it.

 

[caribouhunter]

load is 62 gr h414 with 180 gr. match king

 

[DrMike]

That is a mild enough load that would not normally have caused case separation. Causes for catastrophic case separation could be as innocuous as an undetected flaw in the brass to something as serious as the chamber being out of round. The photo is not as clear as one might wish because of the camera angle, but it appears to my eyes as if the shoulder is quite sharp and pushed forward, leading me to wonder if the neck was touching the lands, creating high pressure. The shoulder certainly looks greater than a 35 degree angle. Was the round hard to chamber? Was the shooter forced to cam the bolt excessively hard to get the round to chamber?

Alternatively, was there moisture/oil/grit on the cartridge or in the chamber? It does not take much oil/grease/grit on a case to cause high pressure.

It would be a good idea to measure the case length of once fired brass to ensure that they have not stretched to excessive lengths with the first firing (a not unusual condition) and to inspect the remainder of the cases to see the condition both of the fired and unfired cases.

 

[chet]

the shoulder doesnt look right to me.

also, the case is scratched and marred. Possibly from being carried in a pocket with loose change and keys. If it came out of the chamber looking like that - dirty gritty chamber causing high pressures as mike suggested.

once fired in someone elses gun = must be fully resized and measured and likely trimmed, especially if that someone elses gun chamber was a little out of round.

just trying to throw out some ideas

there is suit on the sepparations, meaning it happened at or before firing, not during extraction.


all things accounted for, I'd guess it's a bad peice of brass.

 

[pacer97]

What die is he using may be over working the neck hope i stated that right. Is it just the one case.

Best Alan

 

[old #7]

The shoulder angle looks all wrong to me. It seems to have a radius. Or, it looks like some one doesn't know how to cut a chamber. Or the 300 wsm was fired in a rifle of a different chamber.
If not it couls be as simple as bad brass. If it was realy once fired brass it may have been weakened by a polish not meant for brass. Or, maybe the neck was turned too small and it seperated.

 

[baltz526]

looking at the full size picture, It looks like brittle brass.