Yet another pierced primer thread... (pin hole in primer radius)

[358WCF]

The hole is at the radius of the primer cup. Apparently if the metal isn't up to snuff for whatever reason (composition, anneal, impurities, thickness, etc.) small cracks develop at the bend, open up under pressure, & flame cut all things in their path.

This has reportedly been an on/off problem (mostly off nowadays) with Winchester primers since they stopped nickle plating them. Although I've never had it happen personally with WW, I have had Federal 210s do this from 2 different lots.

FWIW Federal CS says it's from poor metallurgy in the primer cup material &/or age/storage conditions. When asked where the expiration date was, they couldn't answer. At least Winchester owns their problems, buying back the primers & repairing bolt faces.

 

[Emmett Dibble]

I looked at the load data from berger and they show a max of 20.4 with the 105/108 and benchmark. I know they are conservative on their loads though. I do not feel its a pressure issue. Id try different brand brass.

You are correct. I know I ladder tested and that is where I ended up with best accuracy. It’s been a minute but I probably went over by a grain or so because I know most data is conservative and don’t worry if there are no signs… Most manufactures won’t recommend a powder that has bad spike habits. Hence a lot of old load data for some powder/applications disappears.

 

[Homerange]

This has reportedly been an on/off problem (mostly off nowadays) with Winchester primers since they stopped nickle plating them. Although I've never had it happen personally with WW, I have had Federal 210s do this from 2 different lots.

I've witnessed 2 shooters have WW primers crack around the edge radius and from what I see from Mr Dibble is different as it's more a blow hole not an edge crack.
At that time it was near impossible to find other shooters experiencing WW primer failures of the same type but one I found in Aussie whom was also pushing things hard.
In both cases (6mm Rem and 270Win) they were hot loads carefully developed a little beyond anything you will see in print.
Both shooters had used WW primers for some good while and both now use something else.

 

[243winxb]

Remington 7 1/2 primers. Fed 205M.

Odd that 2 brands of primer would vent.

High pressure has expanded the primer pockets in 5 firings or less. Reduce the powder charge for the new brass.

 

[Webster]

I've been googling and searching this forum but you can only read through so many threads till your tired of not finding exactly what your looking for....

6X45, happened on second firing but now some cases are up to 4th firing, Remington commercial brass. 2 different loads, one 105 Bergers VLD with 21gr Benchmark, the other 68 Berger flat bottom with 25.5gr Benchmark.

Was having maybe 1 in 20 with Remington 7 1/2 primers, new load with Fed 205M and it dropped to maybe 1 in 50.

Not blowing out through firing pin hole, not around primer pocket, it's blowing a pin hole out in the radius of the primer cup (which obviously flame cuts the bolt face).

Ideas? No heavy bolt lift, primers still show radius, not flattened, firing pin dimple not cratering back out, no flow around firing pin bore, no ejector dimple on the brass, not too much head space, prime off the press and the hand pressure feels normal. 700 action, PTG bolt, factory pin, new Wolf spring...

I'm not terribly worried but it is annoying that my bolt face looks like it has acne.

Looks like the radius on the entrance to the primer cup is larger than what I am used to seeing. No ejector hole swipe. The edges of the primer cup are still rounded but the crown of the cup looks flat. Never saw FP indents like yours. My first thought is always probable excessive pressure. I would have stopped shooting after the first blown primer for safety reasons and so you don’t ruin the bolt. If think if you back off on load it would disappear?

 

[Emmett Dibble]

Looks like the radius on the entrance to the primer cup is larger than what I am used to seeing. No ejector hole swipe. The edges of the primer cup are still rounded but the crown of the cup looks flat. Never saw FP indents like yours. My first thought is always probable excessive pressure. I would have stopped shooting after the first blown primer for safety reasons and so you don’t ruin the bolt. If think if you back off on load it would disappear?

I think I might switch to 3031. It was very accurate (more then Bench Mark actually but about 40fps slower and I am trying to get all I can to knock over the rams at 500 yards. It's already marginal. I didn't quit shooting it because I'm at a match and am there to shoot... (if I thought it was severe pressure I would stop).

 

[Buzz_Man]

I had some older (1980’s to 1990’s) Fed 205M do the same in a Savage 12FV 308 Win shooting lapua 308 Palma (SRP) brass. I replaced the bolt face due to the damage caused from the hot gases cutting into the bolt face. I changed to CCI 450 Magnum primers and no more problems.

 

[Will Henry]

I've seen a lot of rams left standing with good hits from 6BR's, so I reckon the 6x45 is marginal alright! It seems odd to have that sort of failure from two different primers but I think that is the case here. Faulty primers. WH

 

[fkimble@charter.net]

I just wrote about the Rem 7 1/2 problem doing this yesterday in another primer thread. My problem was with the 2 legged anvil version. Rem quickly went back to the three legged version. Look at the anvil in those primers, 2 or 3 legs on the anvils?

Frank

 

[Liven The Dream]

If your Bolt Face needs Help ?
Contact Carlsbad on this Site.
He is the Bolt Doctor.

 

[DaveTooley]

I agree with Will. Faulty primers. If it was related to primer pockets the shooters as well as the manufacturers would have identified that problem decades ago. This is nothing new and not specific to any one manufacture.

 

[Pawnee Bill]

If your Bolt Face needs Help ?
Contact Carlsbad on this Site.
He is the Bolt Doctor.

What he said.

 

[Emmett Dibble]

I've seen a lot of rams left standing with good hits from 6BR's, so I reckon the 6x45 is marginal alright! It seems odd to have that sort of failure from two different primers but I think that is the case here. Faulty primers. WH

Yea, I wanted to go ultimate mouse gun and quality 223 bass is cheaper than quality 6BR brass so…. It’s what I’m playing with.

 

[Highpower-FClass]

I've been googling and searching this forum but you can only read through so many threads till your tired of not finding exactly what your looking for....

6X45, happened on second firing but now some cases are up to 4th firing, Remington commercial brass. 2 different loads, one 105 Bergers VLD with 21gr Benchmark, the other 68 Berger flat bottom with 25.5gr Benchmark.

Was having maybe 1 in 20 with Remington 7 1/2 primers, new load with Fed 205M and it dropped to maybe 1 in 50.

Not blowing out through firing pin hole, not around primer pocket, it's blowing a pin hole out in the radius of the primer cup (which obviously flame cuts the bolt face).

Ideas? No heavy bolt lift, primers still show radius, not flattened, firing pin dimple not cratering back out, no flow around firing pin bore, no ejector dimple on the brass, not too much head space, prime off the press and the hand pressure feels normal. 700 action, PTG bolt, factory pin, new Wolf spring...

I'm not terribly worried but it is annoying that my bolt face looks like it has acne.

Maybe it is just the magnification in the picture but those firing pin indentations look very large and deep.

Could it be that the firing pin is protruding too far, or is deformed, and as a result is doing a number on the structural integrity of the cups? What do the strikes look like on cases where the primer did not pierce?

 

[Emmett Dibble]

I just wrote about the Rem 7 1/2 problem doing this yesterday in another primer thread. My problem was with the 2 legged anvil version. Rem quickly went back to the three legged version. Look at the anvil in those primers, 2 or 3 legs on the anvils?

Frank

2 legged....

 

[Uncle Ed]

My guess is the base of the case is not being pushed back against the bolt face. Meaning the shoulder is being pushed back too far when resizing. This causes the primer to mushroom and bulge at the base. It then blows out the side of the primer.

Below you can see how far the primers were protruding and unsupported when fired.


Below shows how a normal primer is pushed back and reseated.

 

[gunsandgunsmithing]

My guess is the base of the case is not being pushed back against the bolt face. Meaning the shoulder is being pushed back too far when resizing. This causes the primer to mushroom and bulge at the base. It then blows out the side of the primer.

Below you can see how far the primers were protruding and unsupported when fired.

View attachment 1444505

We're all guessing but I'd lean more toward this or something related to it vs two different brands of primers having the same fault, at the same time. But again, I'm guessing here. It may be to different bad primers but the odds of that have to be pretty astronomical.

 

[chop house]

We're all guessing but I'd lean more toward this or something related to it vs two different brands of primers having the same fault, at the same time. But again, I'm guessing here. It may be to different bad primers but the odds of that have to be pretty astronomical.

yes. of all the things that ARE common the primers ARE NOT. i believe an earlier post mentioned 'solving' a similar problem by moving to cci 450, which by the way have thicker cups. so rather than 'solve' maybe a better word is 'mask' in that instance.

 

[Emmett Dibble]

My guess is the base of the case is not being pushed back against the bolt face. Meaning the shoulder is being pushed back too far when resizing. This causes the primer to mushroom and bulge at the base. It then blows out the side of the primer.

Below you can see how far the primers were protruding and unsupported when fired.

View attachment 1444505
Below shows how a normal primer is pushed back and reseated.

About the only way I could bump the shoulder back any less would be to straight neck size only... I measure fired to resized and only bump 0.001 to 0.002....

I think reply #17 is onto something with that. There is a fairly pronounced radius On the case.

I appreciate everyones input. My next HP match isn't till Sept but I'd like to figure this out. Only rifle I have ever had this happen to. It's pocking up my bolt face and I would like to get a handle on it. After the nationals in July I'll get back to work on this in earnest. Everyone has given me several good ideas.

 

[jsn]

Do you uniform your primer pockets? How far below the case rim is the primer seated? Any pics?

Diameter of fired primers, diameter of that "rim" on the top of the fired/split primer? I'm guessing that it's at least .010" larger.

How tight are the primers when seating them, by feel?