primer cratering and boltface pitted

[TackDriver284]

Worked up some loads in .4 increments with RL 25 and H1000 with Berger 210 VLD's and 212 ELD-X. .020 off the lands and Fed. GM 215 Magnum primer

Used 75.8 to 77.4 grains for the ELD and H1000, no pressure signs
Used 76.0 to 77.6 grains for 210 VLD and H1000, no pressure signs until I got to this load of 76.8 grains when I saw primer pocket leaking and weird looking rings on the fired primers. Is this a sign of high pressure? If so, why did it not show any high pressure when I used 77.4 grains for the 212 ELD? Or is this just bad brass?

I saw the boltface of the bolt and I see pits on the ejector and on the face, what can be done to fix this? Or is it OK to continue to shoot it?

I stopped shooting when I saw the leak, and pulled bullets when I got home. Cleaned the boltface with a brass brush and pits are there. Checked the Nosler manual again , min and max load for the 210 to 212 grain bullets are 75 to 79 grains. What am I doing wrong?

 

[Gunner46]

Same lot #'s on the primers and cases for both loads? Same# of firings on each set?

 

[69gto]

I think it is bad primers, you are not going to get that kind of pressure spike with those slow burning powders.

 

[TackDriver284]

Same lot #'s on the primers and cases for both loads? Same# of firings on each set?

Same primers and brass used.

 

[longrangehunter]

So Dewey, could those two nicks on the ejector and the one on the bolt face already had been there? Both the ejector and the ring of the bolt looks like it has been filled or repaired?

Another note, is that new unfired brass? The leaky primer pocket is really bad, but I'm sure you already know that! It they are brand new? I've loaded 300 Jarrett rounds one after the other with 10 firings and they still held the primer to not leak like that, and they got loose after that many.

 

[IdahoCTD]

Blown or leaking primers usually look like smoke comes out. That looks like a bad chemical mixture happened some how. It's really weird how it pooled around the primer and ejector. It does have a ejector mark like it was high pressure but the primer doesn't look like it had high pressure. It's not cratered or excessively flat. It almost looks like it came out of the case as a molten liquid instead of a gas. Did it fire like the rest? Meaning nothing weird was noticeable?

 

[TackDriver284]

So Dewey, could those two nicks on the ejector and the one on the bolt face already had been there? Both the ejector and the ring of the bolt looks like it has been filled or repaired?

Another note, is that new unfired brass? The leaky primer pocket is really bad, but I'm sure you already know that! It they are brand new, and you're not seating the bullet into the lands or are you? I've loaded 300 Jarrett rounds one after the other with 10 firings and they still held the primer to not leak like that, and they got loose after that many.

I looked closely at the brass head, the ejector mark is shown very slightly under the wash of black soot coming from the primer, looks like pitted marks from the burn, on the ejector head and boltface from the blown primer. It was not like that when I cleaned the boltface earlier in the week before breaking it in.

Yes, its unfired Norma brass. I seated the bullets .020 off the lands and I checked OAL length in the chamber before seating. I did everything like I always do with my other rifles. I never had that happen to me in 25 years.

 

[TackDriver284]

Blown or leaking primers usually look like smoke comes out. That looks like a bad chemical mixture happened some how. It's really weird how it pooled around the primer and ejector. It does have a ejector mark like it was high pressure but the primer doesn't look like it had high pressure. It's not cratered or excessively flat. It almost looks like it came out of the case as a molten liquid instead of a gas. Did it fire like the rest? Meaning nothing weird was noticeable?

No, this is the only one. I did not notice anything weird when shooting the loads before this one, or the other loads with RL 25.

 

[longrangehunter]

I did go back and noticed you said .020", and then only to see your reply. It does look more like goop then dried powder residue which should be more like burnt carbon. But those are Norma brass in the picture.

 

[TackDriver284]

I did go back and noticed you said .020", and then only to see your reply. It does look more like goop then dried powder residue which should be more like burnt carbon. But those are Norma brass in the picture.

Oops, indeed its Norma brass. I apologize for the mistake.

 

[longrangehunter]

Maybe it's just the brass. Years ago Lapua had a bad run on their brass that suffered the same thing.

 

[longrangehunter]

So brass or the primer face will flow into the surface of whatever it's up against. That said it would appear that the primer cup metal flowed into the surface of the bolt and that why it looks as it does. But the residue around the primer is something else I've never seen. Normally it's just a partial edge the gas leak goes around, well unless it's blown out, which I have seen first hand by someone not paying attention in the loading room! And those do sound weird.

 

[IdahoCTD]

I think I'd cross section the brass along with another good one to compare them. It could be a weak case head or a loose primer but the way it leaked is just bizarre. It really looks like it was more in a liquid form rather than a gas. You didn't notice any loose fitting primers when you primed the cases I assume?

 

[muleman]

Win Primer?

 

[TackDriver284]

I think I'd cross section the brass along with another good one to compare them. It could be a weak case head or a loose primer but the way it leaked is just bizarre. It really looks like it was more in a liquid form rather than a gas. You didn't notice any loose fitting primers when you primed the cases I assume?

No loose primers at all, all primers were seated very snug in the pocket with a RCBS primer seating tool. I felt each one being seated and all was the same.

I agree that it looked like a flow of a liquid which dumbfounded me.

 

[TackDriver284]

Win Primer?

Federal Gold Medal Match 215

 

[IdahoCTD]

I think I would contact Federal and see what they say. Maybe they have seen it before.

 

[kraky1]

This is why I do 98% of my shooting over a chrono..... I have come to believe over the years you just can't look at appearances and make a decision on what might be happening....ie primer flatness, brass expansion etc etc. For some reason my routine seems to be shoot, look up the Chrono, open the bolt. This way I usually know if I have a huge red flag before I even put my hand on the Bold. Not saying this was pressure related.....just...It's nice to eliminate the factor.

 

[IdahoCTD]

If it was pressure related the case expansion should show that if he measures it. I know a lot of the RUM and WSM cases don't always show pressure or they show very slight pressure and the primer pockets are done. I shot some 180BT's at 3600fps in my 300RUM and it looked like a warm load in other cases but the primer pockets were toast.

 

[kraky1]

I always smile at the speed some people get out of the rums.... I have a 30 - 378 which has more case capacity but I can never get near those speeds without seeing pressure..... the difference appears to be the way Norma brass is made for the 30-378 vs 300 Rum brass. All I can say is that quick load seems pretty well coordinated with my 30 - 378. Some of the" safe" loads I see people running in the 300 rum get near a 80,000 PSI forecast ....ouch!
Then again we have the federal Factory loadings for the WSM that often can never hold a primer pocket after the first firing!