Overpressue Indication?

[whistlersmother]

In anticipation of reloading, I've been picking up range brass. I only pick up what I think are mine, but sometimes other brass gets mixed in also.

Today I thought I'd try out my new tumbler with media on the 9mm brass I've collected.

Some have a red circle to indicate NATO crimped primer. I keep those separate to deal with the crimp when I'm more versed in reloading.

As a novice, I've been reading various websites and the ABC's of Reloading. That's when I came across this fellow in the pictures. As a novice, I assume this is an overpressure indication. The primer protrudes above the head of the cartridge.

I got this brass from On Target at some time in the past. (Hopefully the attachment comes out...)

When this happens, is it best to discard the cartridge?

 

[Mickey the Dragon]

I am also a novice reloader, so I've subscribed to this thread because I'm interesting in the answer. My inclination would be to check the rest of the case of any signs of damage and, as long as the case checks out, remove the primer and reload it. However, someone with vastly more experience will probably be by shortly to correct or confirm that.

 

[44man]

unless the case is bulged or split i generally reuse them.

 

[chale127]

bulged primers happen, inspect the case and reuse if it's good

 

[Traveler]

Bob Mancer suggests using a straightened paperclip to feel the inside of the case and check for cracks. Just bend the tip of the paperclip a bit.

 

[iH8DemLibz]

Maybe a primer hole that's a little big allowing a bit more gas to come through or just deformed from the pin strike.

I wouldn't call that overpressure.

Really good overpressure will leave extremely flattened primers, may wipe out the head stamp information, and will expand the base/rim to the point that it will never go back into a shell holder.

Wish I had kept a 300BLK case from yesterday and taken pictures. Loaded max plus 3 extra grains of H110 to see just how lawyerly reloading books are. (19.3 grains of H110 & 150 grain bullet). I can't recommend it. It turned a small primer pocket into a large primer pocket while blowing the primer out of the case and the rim undercut was way oversized. This was done in an H&R single shot so I knew the gun could handle the pressure spike.

One and a half extra grains and things worked fine. That was enough to make me stick (closely) to what's in the Hornady bible.

 

[j8064]

Bob Mancer suggests using a straightened paperclip to feel the inside of the case and check for cracks. Just bend the tip of the paperclip a bit.

Generally using the paperclip trick can help detect signs of incipient head separation inside rifle cases. It's a very good idea to do when you begin to see a bright ring around the web at the base.

On the OP's question, if the 9mm case shows to be in good condition, I'd reuse it.

Also, that red you see on some primers is often sealer and not an actual crimp.

 

[Jaybeez]

the corners of the primer, the radius from the wall to end, are still quite rounded. pressure signs would mash those into sharper corners.

I dont see any cratering around the firing pin.

looks good to me. looks like a feature of the gun itbwas fired from, similar to glocks leaving square marks on primers.

however... im not at home with my notes. I cannot remember if large fc headstamp is good or bad pistol brass. I recall warnings with older .223 brass and some older pistol brass.

 

[Uncle Duke]

Unless I'm missing something here, I'm not thinking pressure related. I'm thinking gun bolt face or headspace related. For that primer to be pushing outward like that, it can't be physically contacting any resistance to the outer surface of that primer cup. Resistance that would otherwise prevent the possibility of that bulge.

 

[Melnic]

check the case length for grins

 

[j8064]

check the case length for grins

That could have been the original cause of the primer looking like it does.

 

[Swearengen]

Sorry wrong thread

 

[E.Shell]

Unless I'm missing something here, I'm not thinking pressure related. I'm thinking gun bolt face or headspace related. For that primer to be pushing outward like that, it can't be physically contacting any resistance to the outer surface of that primer cup. Resistance that would otherwise prevent the possibility of that bulge.

Agreed, it's obviously an artifact from a bolt face blemish.

Looks like the bolt face had damage around the firing pin bore, maybe erosion from leaking primers caused by a sharp firing pin.

If the case was too short (excessive headspace in a 9mm), the primer would have been backed out upon ignition, then reseated at full working pressure, causing the edges to square up. The face of the primer cup would have remained flat and could not have bulged out.

I'd wager (void where prohibited by law) the case length is within spec and that it loads and functions normally.

 

[whistlersmother]

With a paper clip, I can not discern any cracks inside the case around the circumference.
I don't see any bright ring, but there are what appears to be scratch marks - I did pick this up off the floor at the range.

Interestingly, there is a mark _in_ the extractor groove from the extractor - now if I just had access to all the barrels of fired cases at MSP, I could find the one gun it came from...

Length is 18.85mm after removing the spent primer with a small screwdriver through the flash hole. (Did not run this through any sort of die.)
Mouth is 9.62mm, at the webbing 9.87mm, head measures 9.88mm.
Flash hole doesn't _appear_ any larger than the other 9mm luger I'm using for comparison.

Thanks for your help of a novice. I will mark this case, eventually reload it, and fire it.

(As for the Winchester 9mm NATO case, it may be sealed as j8062 suggested. I'm putting those on the shelf for now. Lots of stuff to learn before throwing something else into the mix.)

 

[toolness1]

I have a FEG Hi Power clone that has either an oversized firing pin hole, or undersized firing pin, and all my primers crater in them (although not exactly like yours looks).

Also, I was freaking out on some of my reloads because I was getting really flat, sometimes cratered primers from published mid-range loads. I was using S&B small pistol primers. I tried a batch of the same loads with CCI primers, and they all looked normal. So, some primers are just softer and you will get false high pressure signs.

I see it looks like your issue is different by what some of the other posters (who are smarter than me) are saying, but I wanted to share this info anyways.

 

[Blacksmith101]

Here is a good reference for identifying pressure signs. Remember if in doubt get another opinion.

http://massreloading.com/reading_pressure_signs.html