Cratering Primers

[Husky user]

I have a new Weatherby Back Country in 6.5 RPM.
From day one it craters the primer.
Factory ,reloads all of them.
I contacted Weatherby and they said they thought maybe the firing pin spring was weak.
Just made it harder to spot the start of hi pressure.
I contacted them about another problem I thought might be covered by warranty.
Said maybe they could fix the firing pin spring at the same time.
Now they tell me all RPM strike the primer hard.
Told me to check to make sure the firing pin was not sticking out of the bolt face when cocked.
I am inclosing a picture of some fired cases(mix of factory and reloads)
Any ideas from the forum?

 

[Wedgy]

A couple things could be in play here. You could have a sloppy firing pin hole, very common on factory rifles, simple solution is to have it bushed by someone like Gre-tan. You could also have something giving you high pressure like not enough neck clearance. Can you slide a bullet in a fired case ? Any other signs of pressure other than the cratering ?

Bush Firing Pin Hole & Turn Pin $80.00

Bushing the firing pin hole and turning the firing pin sounds small but this one operation to the bolt has so many benefits it's hard to believe. The biggie is it has to be done correctly to work as a total benefit. It took two years to perfect my system to get all the good out of this...

www.gretanrifles.com

 

[Husky user]

It does it on low pressure loads and factory loads.(all loads)
I have ran some loads way up till they show lots of pressure!
I will bring up the sloppy firing pin hole,see if they would fix that on warranty!
This is a $2400 rifle,I would expect better!

 

[nealm66]

Those primers look flat as well. Have you chronographed any of the factory ammo to see how close to advertise fps?

 

[nso123]

I am going to lean toward the firing pin hole, too. AI rifles used to have this issue as well.

 

[Husky user]

Those primers look flat as well. Have you chronographed any of the factory ammo to see how close to advertise fps?

Yes the cheap factory 140 run 2902-2963
The 140 accubond runs 3066-3105

 

[nealm66]

Man, that's a pretty big spread. I've only chronographed the 257 premium 110 noslers and they were only about 4fps difference. Somethings not right.

 

[MagnumManiac]

Here is my theory and the way to confirm this theory.
Your firing pin hole has been beveled, the primer cup is flowing into this bevel…..take a magnifying glass, a good bright light and look at the firing pin hole in the bolt face.
If you don't have a magnifying glass, take a close up pic with your phone with plenty of light, blow it up and look at the firing pin hole. If there is a bevel, that is your issue.
Every Remington I own does this and they all have a beveled firing pin hole… it is annoying and the fix is to bush the bolt face.

Cheers.

 

[L.Sherm]

Man, that's a pretty big spread. I've only chronographed the 257 premium 110 noslers and they were only about 4fps difference. Somethings not right.

I've seen 100fps E.S in Horandy factory 300 win mag ammo.

 

[JAYgs8163]

Have the firing pin bushed. I had this issue also on a 6.5PRC and a 6.5-284. GreTan does great work but his books are closed. @GNERGY does this type of work also. He did my last one and is very affordable and work quality was top notch and very quick turn time.

 

[rsbhunter]

I'm going with bushing the firing pin hole/bolt face. Have a Savage 6mm Norma Dasher that did the same thing....sent it off and for $80.00 or so fixed that problem. The primers now may show some flatness , but catering is non existing.....best money I spent in a while.. rsbhunter

 

[Coues110]

What does it hurt, other than to make one think they are seeing pressure signs? I always look for flattened primers and ejector marks on brass and compare the cratering, which gets worse with higher pressure.

 

[JAYgs8163]

What does it hurt, other than to make one think they are seeing pressure signs? I always look for flattened primers and ejector marks on brass and compare the cratering, which gets worse with higher pressure.

For me if the cratering is bad enough you can't get the cartridge into the resizing die. I've had this happen a few times but not anymore since bushing. I use Redding competition shell holders which have tight tolerances though over a standard shell holder.

 

[ButterBean]

@Husky user

Do you have a hard bolt lift ?