Too much pressure?

LUTNIT

LUTNIT

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The part coming up on the right side of the right case is actually a rib of brass that flowed into the ejector hole around the ejector plunger. It forms a semi-circle around one of the ejector marks.
The "N" from the "WIN" stamp on the other side of that rib of metal is almost completely obliterated.
I cleaned them already but there was definitely some gas leakage on the far side of the left case/primer (doesn't show up in the pic).
You can see a split in the case wall starting on the right case near the bottom of the frame.

I like the follow the "road to accuracy" but I think the guy who loaded these may have been following the "road to facial reconstruction surgery".
Didn't recognize the guy shooting these. Was a public day (weekend) at the range I go to. He was just packing up as I got there and didn't look happy. Found probably 15-20 cases in similar condition.

Think they're safe for me to reload? :p kidding of course
 
Jeeze, if you see that guy again give him a hug and offer your condolences. There are better ways to compensate than making your face explode.
 
There is something more than simple over-pressure happening there. Those are the strangest looking fired primers I have ever seen.
 
It may not be pressure.
I've never seen blanked primer strikes and prominent ejector marks without flattened primer edges as well.
Hard to tell from pics, but they don't look too much like reloads.
Will hazard a guess those were factory loads fired from a rifle with very excess headspace, soft firing pin spring, and a slippery chamber, athough you'd think the primer cups would be protruding if that was the case.

Very strange.
Was buddies rifle a self loader?.
 
Why buy a 300 when I can just jam more powder into these!
I was trying some new reloads in my rem. 7600 and savage model 10 today...both .308...was looking for over pressure signs. Atleast now I know what too look for. Wow...never seen that before, I stress over flat primers.
 
Something is very strange about those empties.
The lack of primer flattening indicates a very light load. And how did the centre of the primers blow out in such an odd, dish shape?
And why wouldn't the bolt face prevent the piece of metal case from extruding like that?
I wouldn't even hazard a guess as to what we are looking at.
 
Hmmm. Just saw a video on reusing primers. You take out the anvil, take the dimple out of the cup, add a cap (no really I'm not kidding), re insert anvil.


Not saying it is what happened, but sure would explain those primers.

Primers a way to rounded for over pressure.

Other possibility is that the bolt firing pin hole has worn out....or has been drilled out.
 
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Are the primer pockets loose? If not, the pressure wasn't overly excessive.

There's zero powder leakage, so I think not.

The extrusions on the face of the base and the primer are. Very odd. Federal brass is relatively soft IMO, but that still doesn't explain it.
 
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LUTNIT said:
Click to expand...

I agree with some of the other guys, there's something other than pressure at work there. One sign of high pressure is when the bevelled edge of the primer pocket is obscured by the flattened primer, and there is no sign of that. A sign of very low pressure is when the primer has backed out of the primer pocket, and that doesn't appear to be the case either. It almost looks as though the primer flowed into the firing pin recess in the bolt face. Neither is there a distinct line above the web of the case which would be a sign ot excess head space, (or shooting a .308 Winchester in a .308 Norma) indicating where the case was about to seperate, and since the web of the case is not obvious, it would appear that this brass was not full length resized prior to firing. The tear in the case head on the right hand cartridge is curious, and I'm at a loss to explain how that might happen. Perhaps he removes the bolts from his rifles for storage, and put the wrong bolt in his rifle, but that's probably a stretch.
 
Wow! I really don't know what to make of it other than simply ..... there is obviously something wrong. I certainly would have halted the experiment long before 15-20 rounds like this!was lucky!
 
I didn't see anyone mention Federal and soft brass or the fact the cases were fired twice and the brass flowed into the ejector two times.

Below in my brass scrap bucket are primarily factory loaded Federal cases that the primer pockets stretched so badly the cases were not fit to reload. These cases were never reloaded and were only good for one firing.

193natorejects001_zps87560a0a.jpg


Below a .175 pin gauge that has been inserted into the over sized primer pocket, meaning you could push the new primer in with your finger.

looseprimer005_zps7fe118e2.jpg


I'm going to guess and say soft brass and the cases were over resized meaning excessive shoulder bump causing excess clearance between the bolt face and the rear of the case. (head clearance)

And guess number two is they were shot in a relatively new Remington 700 with a beveled firing pin hole. Meaning it wasn't an old rifle with excessive headspace but a "cartridge" with excess head clearance.

boltface2_zpsdf1f12bc.jpg


Don't ask me how I know all this but I gave a new Remington 700 with the bolt pictured above to my son who doesn't reload.

And if you Google Federal soft brass you will see many photos just like the OP posted photo.

Below is showing "head clearance" and excessive shoulder bump meaning the die was not adjusted properly and set up as per the die instructions making hard contact with the shell holder. (press cam over)

HEADCLEARANCE-a_zps1a9a1011.jpg


Below when the cartridge is fired the initial pressure causes the primer to back out of the primer pocket and contact the bolt face. As the pressure increases it reaches the point that causes the brass to stretch and meet the bolt face.

HeadClearance_zpsf30a3af1.gif


If the head clearance is great enough the firing pin acts like a cookie cutter and punches the center out of the primer. The .223 case below was fired in a over gassed AR15 and the anvil plugged the gas leak.

piercedprimer-2_zps2d386fad.jpg


softbrass_zps0b71aba5.jpg


FC headstamp = Faulty Cartridge = soft brass
 
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Tazzy said:
Bolt not locking up properly on a semi auto?
Click to expand...

Not quite, a over gassed semi-auto like a AR15 will cause the bolt to unlock and start moving to the rear before the case releases its grip from the chamber walls. If it were a semi the base of the case would have "brass swipes" and smear the brass that flows into the ejector.

Only the case on the right has one defect at the letter (N) because it was located at the very edge of the ejector hole in the bolt face. The case on the left over the letter (C) did not deform, so I'm guessing it was not a semi-auto. You will see this a lot with commercial cases that are not made as hard as military brass.

Case-Head Swipe

http://www.shootingillustrated.com/index.php/8720/case-head-swipe/

556hard-a_zps7570e6b0.jpg


hardness-a_zps8d54ad66.jpg


Our American made Lake City military cases are harder to better withstand larger diameter military chambers and longer headspace settings.
 
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