primer pocket blow out.???

[Bob Wright]

Bob,
I get what your saying, but I'm not sure your getting what I'm saying. Overworked brass is harder than new brass do to work harding. If anything, it would show less pressure.....not more. Back before we were lucky enough to have this kind of knowledge at our fingertips, guys would use nail polish to hold primers in spent brass and keep shooting it. Primer pockets have nothing to do with that case looking like that. Something else IS wrong, there is no way to tell from here what it is, but I highly suggest that you figure that out before you move forward.
I read a lot on this site, but don't post all that much. I felt like I needed to say something here.
I sincerely hope you don't hurt yourself.
Good luck man

It's fire formed from new brass, neck sized .003 tight to the bullet dia. thereafter. The failure was at the head. I don't know if that helps understanding what the failure is. I am pursuing new loads and giving a lot of consideration to what happened. See my last post. Thanks.

 

[Edd]

How much H4831SC powder were you loading?

 

[Pdvdh]

There's a Thread on this Forum discussing steps in the process of reloading cartridges. I describe an invaluable QA/QC step in my reloading methods.
Charge all cases with powder prior to seating any bullets. Then with all powder charged cases in the reloading block, visually inspect and compare the powder height in each case using a flashlight. You'll be able to identify suspect powder charges. Reweigh the powder charges in any case that looks to have a different volume of gun powder before seating a bullet in any of the cases.

As others have noted, your case wasn't slightly overpressure. That cartridge pressure was high enough to pose an injury risk. More than just an inconvenience.

The brass case heads will always be the first point of failure as pressures become dangerously high. I know, always is a big word. About the only time another part of a healthy firearm will fail first, is if the muzzle of the barrel is plugged with mud, or some other foreign object. Then the barrel will commonly bulge just prior to the blockage.

When your friend's barrel was fired downrange, the odds are good his case head looked worse than yours, if he ever found it.

 

[Pdvdh]

"Revisiting brass processing and loading order"

That's the title of the Thread that discusses how members go about reloading their cartridge cases. Pretty good read to help avoid overloaded reloads.

 

[CaptnC]

.
Then with all powder charged cases in the reloading block, visually inspect and compare the powder height in each case using a flashlight.

phorwath,
There is wisdom in your reply, but you think you could catch a 2 grain over charge? I guess it will really depend on the cartridge. Double charges always over fill the case if you forget to move the funnel, so that one is a no brainer!

I'm going to try it this weekend just for personal knowledge.

 

[Deleted member 46119]

"Revisiting brass processing and loading order"

https://www.longrangehunting.com/threads/revisiting-brass-processing-and-loading-order.196768/

@phorwath makes a very good point in the above thread about QA/QC checking your charge. His method works for him and many others. It is taught in manuals and classes. I am not rebutting or attempting to suggest that his method is without merit, just the opposite, it is very good. However, I am a major klutz. Having more than one case with a charge in it means that I will spill powder into a case in the reloading tray. Been there done that. Visually not a visible problem. The second QA/QC check of weighing the charged case caught the error. This happened enough times that I abandoned having more than one case charged. I measure a charge. Double check the charge on a separate scale, decant the charge into the case and seat the bullet.

Not saying that you accidentally added powder.
Not saying that your powder measure over dispensed.
Not saying @phorwath method on QA/QC is not good.

That is why I started the above referenced thread.

 

[Deleted member 46119]

Back to the problem at hand.

There are a large number of assumptions aka "ifs" that can not be satisfied with facts. As a result we are left with probable truths.

Pretty undisputable, it was an over pressure situation.
"If", there was an accidental over charge, no further action is required except to modify the QC/QA portion of charging cases.
"If", it was an accidental long seated bullet jammed into the lands for a charge that needs some free bore, no further action is required except to modify the QC/QA for checking COAL.
"If", if, if. if....

IMO: it boils down to a head scratcher for @Bob Wright

and

A review of by all of us on our QC/QA for reloading.

 

[Bob Wright]

I know this is not the "right" way to precision reload but my wife's rifle is sighted in at 100yds because we normally hunt in a very small controlled area. So when I was making brass for her 6.5-06 I was just grabbing once fired 30-06 brass without much attention given to manufacture. I ended up with roughly a dozen Federal cases out of 40 that I loaded.

I took it the range to make sure it was dead on. I normally put the fired case in the box head stamp up. I was playing more attention to the target than the brass when I noticed 4 cases had a little soot around the primers. Nothing like Bob had but a small amount of gas had leak back.

I sorted out all the unfired Federal cases because they were loaded as a "batch" loaded to gether just incase I had charged them too much. I got home pulled all the bullets and the charge was almost exact. None were over .2 of each other and the charge was right.

I'm a range brass rat...so my eyes are on the ground all the time. I picked up around 25 300wsm cases.

This week I was prepping all my WSM brass and was trimming brass when I found one of those pick ups had a split neck...sure enough...Federal! So they all went in the scrape brass bin!

PLUS the flash holes are nearly blocked. I have to get a drill out on one case to break the "chip" loose...

Winchester brass has cleanest flash holes on average, even compared to Lapua brass.

Yes, I agree with changing brass to a Winchester or Remington. The Nosler (Norma mfg.) Is getting a lot of complaints for soft condition. I neck size only and noticed there was light neck tension on some I broke down, others were as tight as I expected. I have been thinking I will toss the 3/4 pound of powder I used for this load and go a different route. Something might of have been wrong in the powder. I have not used any other powder so inadvertanly mixing another powder is practically nil. I have no way of testing it, so out it goes. Alliant and Hodgdon have a great selection of slower powders and stable temps. Back to the drawing board.i have 40 years in aerospace manufacturing and contrary to some beliefs, out of spec on any component is a no-go for me.

 

[CaptnC]

Try the H1000...it is a low pressure powder. That's why I use it in my 300wm built a mauser action. Acceptable velocity without the pressure.

 

[CaptnC]

Just noticed you said some had weak neck tension. A buddy if mine who shoot a lot...I mean a lot of 3 gun competition said he has seen some gas guns push the bullets back in the case...end result was blown up guns...both pistol and AR platforms.

Bob are you one who loads a full mag when shooting at the range.

Even my 300wm mag...control fed from a AI mag I load them one at a time.

 

[Pdvdh]

phorwath,
There is wisdom in your reply, but you think you could catch a 2 grain over charge? I guess it will really depend on the cartridge. Double charges always over fill the case if you forget to move the funnel, so that one is a no brainer!

I'm going to try it this weekend just for personal knowledge.

Yes, I do think the human eye will notice the difference in the powder column height measuring two grains of powder weight.

More importantly, visible inspection will easily detect a casing overcharged with sufficient powder to expand a normal strength case head by 0.050". If this casing had normal case head strength (wasn't a defective casing), then I'll go on record as stating it would
have required more than 2 grains of additional powder to permanently deform/expand/enlarge this casing 0.050", compared to a normal load expanding the case web by less than 0.0005". In my opinion, 4 or more extra grains of H4831 powder would have been required to bulge a 7mm RM case to this extent. Even two grains of excess powder will be visible inside the casing, in the midst of other properly powder charged cases. 4 or more grains of excess powder will be screaming out. You'll probably even see a little red flag protruding from the case mouth at 4 grains excess powder.

The value of the visible inspection of the powder charges in the casings before seating any bullets is the prevention of an overcharged case that shoots the barrel down range along with the bullet.

 

[Edd]

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?

 

[CaptnC]

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.

 

[Bob Wright]

Try the H1000...it is a low pressure powder. That's why I use it in my 300wm built a mauser action. Acceptable velocity without the pressure.

I was just looking for pressure signs on my 175 Nosler loads with Retumbo and at 2850 fps there are healthy looking primers an zero ejector pin marks. Accuracy is good. H1000 is a good powder.