Help with pierced primers

[swampy308]

What would cause this?
Reloading for 22-250 ruger, used winchester, remington, and federal brass. Win LR primers, IMR-3031 powder, and winchester 55gr PSP.
Working up loads for each brass type was 5 each 31gr. 31.5gr 32gr, and 32.5 gr.
Winchester grouped best at 32.5gr with .60" group, remington grouped best at 31.5gr with. 69" group, federal brass is where I started having problems, first shot with third group at 32gr had ruptured primer so I stopped there and rechecked the other brass and found the fifth shot from the first load done the same thing, puzzles me what would cause this weak brass maybe.
Also each box was shot on different days with a couple minutes between each shot, temperature was in the mid fourtyies.
I have picture but don't know how to post it, pin hole on outside edge of primers. Eny thoughts are appreciated.

 

[lugerstew]

My Sierra load data show about 30 to 34 grains for that load, so it doesn't seem like you are at max load.
Did you have any other pressure signs like hard bolt lift? I assume you didn't have a chrono.
Have you shot any factory ammo thru this gun, or is it new to you?

 

[swampy308]

No other pressure signs, and I shot 5 winchester factory rounds before to fall the barrel, also forgot the primers backed out about 4 to 5 thousands.
I also just pulled bullets from the Other nine and decaped the primers, and primers came out easily.

 

[Unclenick]

Since Federal showed a problem first, I suspect the primer pockets have expanded and aren't sealing properly. Federal is known to have that problem in some chamberings. If only the Federal is doing that, I would retire it.

The other thing you mentioned was primers backing out several thousandths. That is normally a low-pressure sign because, at full pressure, you expect the case head to stretch back and reseat the primer to flush.

I was going to say excessive headspace can cause the leakage problem, but your "4 to 5 thousandths" of back-out show it is within the normal range.

 

[mehavey]

(Delete -- OP answered it was edge leakage)

 

[swampy308]

Thanks for your replies, I have already scraped this brass. Kinda freaks you out when the case head comes out all sutty.

 

[44 AMP]

any idea how many loads were on the cases? Any of the HOT??

Brass does wear out. if you can retrieve any of the cases, check them for signs of impending head separation.

Primer edge leakage is a sign of enlarged primer pockets (or seriously bad primers) and if the case heads have enlarged that much, partial or complete head separation is on the way.

By my old books your loads in the 32gr range fall in the middle so it shouldn't be a pressure issue.

DO check your bolt face carefully to see if there was any gas cutting of the metal when the primers leaked. Probably best to clean everything too...

 

[swampy308]

3rd loading with these, did check for separation no sings found I use same primers in two different 308 win, and 260 rem with out failures.
Cleaned and checked bolt face, bolt face dose have slight gas cutting.

 

[44 AMP]

No other pressure signs, and I shot 5 winchester factory rounds before to fall the barrel, also forgot the primers backed out about 4 to 5 thousands.

I forgot to ask, were the factory rounds ok? Or did they have the primers back out also??

3rd loading with these, did check for separation no sings found

3 loading then fail is a lot less than usual. Makes me wonder if there is something else going on, with your rifle, or perhaps, your loading process.

On the other hand, if your rifle is running .6-.7" groups, is may be better just to learn to live with short case life. Your call, of course.

 

[Unclenick]

If they are just Federal cases that are failing, I think that indicates all else is normal because Federals are known to do this in some chamberings. We even had a post by someone shooting Federal factory ammo in one of the magnum chamberings who was having the factory primers fall out when he ejected the cases.

 

[swampy308]

Federal was only brass that had the primers to back out on, after I thought about it a while only difference in the loading process between the three brands is I neck sized the Remington, and Winchester the Federal was brass I had from a different gun and I full length sized those.

 

[tangolima]

Pierced primers and backed out primers are two different things. I thought the op was having both. Soft brass don't do both.

-TL

Sent from my SM-N960U using Tapatalk

 

[Unclenick]

He's got a pinhole piercing described in the OP, but didn't have them on the earlier firings. When a primer pocket gets loose, the primer backs out of the pocket earlier in the firing event. This increases the opportunity for the head of the primer to mushroom outward and get pinched when the head backs up to try to reseat it. This can make it weak enough to pierce. I would expect the primer to look significantly flattened in this instance.

 

[Nevmavrick]

A few years back Winchester had a few lots of WLR primers that suddenly would pierce at the edge of the primer. It seemed to be caused by a slightly-hard primer cup, I believe.
The damage caused is a burning of a hole in the bolt face.
Winchester asked that the primers be sent back, and they would replace them.
They published the lot numbers, so they were pretty well identified.
You can go to their website, and if that doesn't work, contact them.
Have fun,
Gene