primer pocket blow out.???

[Bob Wright]

IMO...the biggest draw back to digital scales is you weigh to the proper weight...not like a beam scale where the weigh is pre set weight.

I have to write it on paper by my scale (especially getting ready for a OCW or ladder test) so I don't mis-charge a case.

I had to send my digital back to the manufacturer for testing. The triple beam I have is difficult to use. Im looking at other scales to double check. My digital was showing pulled cartridges were .8 gr. Variation. Bad....

 

[Bob Wright]

I'm finding it difficult to think pressure between the bolt face and the case pushed the case forward .050". If the case was a proper fit in the chamber, it would require shearing the belt and pushing the shoulder back to do this. There would also be opposing pressure inside the case.

If the case was already positioned there when chambered, not headspaced by the belt, not headspaced by the case shoulder, but headspaced by the case mouth jammed into the transition angle, it could cause a high pressure condition.

What is the history of that case? Have you checked your chamber with a headspace gauge?

The belt is .050 wide on the breeched case with evidence of shiny brass where it sheared in a forward direction. Crazy. All this brass needs to go, and start up with 10% off, new loads just so I can redevelop a load and have no markings to confuse pressure readings. I have 100 rounds that were in multiple OCW tests that 2 failed. Found a great web site explaining many pressure signs. What little signs I have in the brass lot is so subtle but from subtle to kablooie is not far away. I think starting over after removing the barrel for a muzzle break and damage inspection should be the best course of action then start back with OCW. Most existing brass are over size in primer pockets...

 

[Bob Wright]

I'm finding it difficult to think pressure between the bolt face and the case pushed the case forward .050". If the case was a proper fit in the chamber, it would require shearing the belt and pushing the shoulder back to do this. There would also be opposing pressure inside the case.

If the case was already positioned there when chambered, not headspaced by the belt, not headspaced by the case shoulder, but headspaced by the case mouth jammed into the transition angle, it could cause a high pressure condition.

What is the history of that case? Have you checked your chamber with a headspace gauge?

Brass has 3 loads through it.The primer to brass height was showing .001 headspace but that will be verified at gunsmith. The belt damage from .100 wide sheared to .050, is fresh metal. Appears the gases got behind the case head and shoved it forward, plus extractor tore into the rim. It appears so at this point.

 

[Bob Wright]

Brass has 3 loads through it.The primer to brass height was showing .001 headspace but that will be verified at gunsmith. The belt damage from .100 wide sheared to .050, is fresh metal. Appears the gases got behind the case head and shoved it forward, plus extractor tore into the rim. It appears so at this point.

No, I am wrong! I measured to the counter bore in the chamber for the mag belt. This expanded radially into it. Part of the belt lies outside.

 

[Pdvdh]

After looking at your side profile pic of the fired case, glad you're OK.

Some believe a 0.0001" measuring device is required to identify case web or case belt expansion. Not in this "case".

I'm surprised you didn't see any evidence of gas impingement against the bolt face, which is very common in many blown primer incidents.

 

[Bob Wright]

After looking at your side profile pic of the fired case, glad you're OK.

Some believe a 0.0001" measuring device is required to identify case web or case belt expansion. Not in this "case".

I'm surprised you didn't see any evidence of gas impingement against the bolt face, which is very common in many blown primer incidents.

There is only a faint ring of of grey on the bolt face but no etching at all. I keep getting stuck on loose primer pockets problems and maybe I shouldnt. I have seen and experienced a heavy bolt lift with these cases, using Reloader powder and and same Nosler brass on my other Remington 7 mag. I was working up loads from 10% off and before I got to the max published load I hung up one case. I just don't know. Bad lot of cases?

 

[elkaholic]

Bob and Paul, this sounds eerily familiar with the 30/375 S.I. Hornady brass!!

 

[Bob Wright]

Bob and Paul, this sounds eerily familiar with the 30/375 S.I. Hornady brass!!

I thought the Reloader powder shouldn't have hung up a case below max published data. So I quit using the powder and went to Hodgdon.

 

[Pdvdh]

Yes, there are similarities. My blown primer was much less impressive, yet still concerning.
If the elastic yield limit (intrinsic property) of the brass is inconsistent straight off the factory production line (which is impossible for the reloader to know ahead of time), then the only realistic option for the reloader is to move on to another brand of brass from a company with an impeccable reputation for consistently high quality brass.
Which is exactly what I've, replacing my cases with RWS brass.

 

[Bob Wright]

Yes, there are similarities. My blown primer was much less impressive, yet still concerning.
If the elastic yield limit (intrinsic property) of the brass is inconsistent straight off the factory production line (which is impossible for the reloader to know ahead of time), then the only realistic option for the reloader is to move on to another brand of brass from a company with an impeccable reputation for consistently high quality brass.
Which is exactly what I've, replacing my cases with RWS brass.

Thanks for your insight. RWS is available through which supplier? I do want a change to new brass and start completely over....

 

[elkaholic]

Huntington dies is the only source that I know of. I get it there all the time..... Rich

 

[Pdvdh]

Yes, there are similarities. My blown primer was much less impressive, yet still concerning.
If the elastic yield limit (intrinsic property) of the brass is inconsistent straight off the factory production line (which is impossible for the reloader to know ahead of time), then the only realistic option for the reloader is to move on to another brand of brass from a company with an impeccable reputation for consistently high quality brass.
Which is exactly what I've, replacing my cases with RWS brass.

There's not 1 in 1000 reloaders that collect and document case web diameters pre- and post-initial case firings of brass during load workup, as I did in the instance of my blown primer. This data allowed me to confidently conclude - after the fact - that a Hornady case with 3.2gr less powder, producing 90+ fps less MV at a lesser pressure, expanded the case head more - resulting in a blown primer, while the Hornady case with 3.2gr more powder and 90+ fps additional MV (and more associated pressure) expanded the case web measurably less - such that this case held its primer. Both Hornady cases were from the same Lot of manufacture. Really leads to only one conclusion: The Hornady case heads had different, inconsistent case head strength.

One more observation. Hornady is currently the only manufacturer of 375 Ruger cartridge cases, to the best of my knowledge. Nosler used to market 375 Ruger casings for reloaders under their Nosler case head stamping. The Nosler brass had to be coming from Hornady, because no other company was manufacturing the 375 Ruger cartridge cases, and Nosler wasn't manufacturing it themselves at that time - 5yrs ago. Still don't think Nosler is manufacturing cartridge cases in their own plant.

Low and behold, Nosler ceased to offer 375 Ruger brass on their web site, and hasn't for over one year now, based on my research and understanding. Why might that be? Is this corroborating evidence of inconsistent strength/quality of the Hornady brass? I certainly wouldn't risk the reputation of my brA$$ if I became aware of problems with cartridge case quality being produced by my supplier, which was then dressed up for sale by my company under my company Brand.

Bob, here's the link to my Thread covering my blown primer incident. A long read, but you might have the interest:
https://www.longrangehunting.com/threads/blew-a-primer-_-analysis.197020/

 

[Bob Wright]

There's not 1 in 1000 reloaders that collect and document case web diameters pre- and post-initial case firings of brass during load workup, as I did in the instance of my blown primer. This data allowed me to confidently conclude - after the fact - that a Hornady case with 3.2gr less powder, producing 90+ fps less MV at a lesser pressure, expanded the case head more resulting in a blown primer, while the Hornady case with 3.2gr more powder and 90+ fps additional MV (and more pressure) expanded the case web measurably less and this case held its primer. All Hornady cases were from the same Lot of manufacture. Really leads to only one conclusion: The Hornady case heads had different, inconsistent case head strength.

One more observation. Hornady is currently the only manufacturer of 375 Ruger cartridge cases, to the best of my knowledge. Nosler used to market 375 Ruger casings for reloaders under their Nosler case head stamping. The Nosler brass had to be coming from Hornady, because no other company was manufacturing the 375 Ruger cartridge cases, and Nosler wasn't manufacturing it themselves at that time 5yrs ago. Still don't think Nosler is manufacturing cartridge cases in their own plant.

Low and behold, Nosler ceased to offer 375 Ruger brass on their web site, and hasn't for over one year now, based on my research and understanding. Why might that be? Is this corroborating evidence of inconsistent strength/quality of the Hornady brass? I certainly wouldn't risk the reputation of my brA$$ if I became aware of problems with cartridge case quality being produced by my supplier, which was then dressed up for sale by my company under my company Brand.

Bob, here's the link to my Thread covering my blown primer incident. A long read, but you might have the interest:
https://www.longrangehunting.com/threads/blew-a-primer-_-analysis.197020/

Just by your research and documentation, I am impressed beyond words. It looks like an engineering failure report as I have seen (many) over the years at my work with turbine engine manufacturing. It sounds similar to my experience. Admit I am stumbling over my results, and re-assesing. Read a great web site author on pressure signs and learned a lot by his observations tied to photographs. Subtle changes, quickly go from acceptable to destruction. Will be taking a much harder look on the new OCW I have ahead of me.