Loose primer pocket.

[MoBoost]

I have a lot of Norma 270wsm brass. It is once fire with pretty stout load. Prepped it ... primers set too easy.

Load was stout - but there where no pressure signs.

I cut a case with the "loosest" primer pocket to see if there are any pressure signs inside:

What the heck?

 

[HiredHand]

Is that cracking around the primer pocket? Educate my inexperienced eyes.

 

[MoBoost]

No, nothing - everything is perfect. I guess, the fit to chamber is very tight, but there is so much pressure that it was swedging the head.

 

[Calamity Jake]

Is this factory loads or your reloads? If your reloads then I think that backing off a little is a safe bet, there's no need to push to the limit.
If factory loads, try a different brand.

 

[MoBoost]

Reloads. Yeah, backing it off defeats the purpose of having WSM ... oh well

 

[Rod Snell]

Reloads. Yeah, backing it off defeats the purpose of having WSM ... oh well

In loading some WSM for a relative, I finally read the fine print about the WSM's extra performance: they are loaded hotter than the standard caliber they use for comparison, on the theory that all WSM guns are new and strong..
If I take my .270 WIN and load it with 4831 like we did 30 years ago (scoop the case full and scrunch a 130gr Nosler Partition down compressing the powder) I get speeds comparable to WSM---and very short case life.
One of the boxes of WSM once-fired factory brass I was given to reload were ALL ruined by the factory overload, and went straight to the recycle bin.

 

[NikatKimber]

I have a lot of Norma 270wsm brass. It is once fire with pretty stout load. Prepped it ... primers set too easy.

Load was stout - but there where no pressure signs.

I cut a case with the "loosest" primer pocket to see if there are any pressure signs inside:

What the heck?

For those of us that don't get it, what are we looking at here?

 

[HiredHand]

What brand of primers? I wonder if they were on the small side of spec.

 

[milsurp]

I wouldnt worry about it unless the spent primers are falling out on ejection and falling onto the other rounds. As long as the primer is in until you close that bolt on it its ok. The bolt face will hold the primer in.

 

[MoBoost]

For those of us that don't get it, what are we looking at here?

I was looking for any kind of overpressure/headspace signs - brass flow, anything.

What brand of primers? I wonder if they were on the small side of spec.

CCI Magnums. Federal supposedly are bigger - I guess I can try them.

I wouldnt worry about it unless the spent primers are falling out on ejection and falling onto the other rounds. As long as the primer is in until you close that bolt on it its ok. The bolt face will hold the primer in.

I could try that - even though the primer barely seats, there was no "blow through".