Cratered primers ?

[Varmint Hunter]

I have a 30Nosler semi-custom rifle that will crater a Fed 215M primer with loads below book maximums. There is no other indication of pressure at these moderate load levels. I'm assuming that the Rem 700 bolt just has an oversized firing pin hole that causes the cratering.

I've had the bolt bushed on another rifle but I'm wondering if there is a real benefit to doing so. Other than the cosmetics of not getting a cratered primer; is there any real benefit to having the bolt bushed?

 

[David_h]

I read up on it when I had cratered primers with my 300 WSM BAR. Since I was not having any other signs of pressure I was going to live with it. However it started showing some pierced primers so I sent it to Browning and they replaced the gun. New gun has some cratering too but not as pronounced so I'll live with it.

If you live with cratered primers then you have to realize that there is one less warning sign to be used to assess high pressure. But you will still have the signs on the brass case (swipes, ejector marks) and you still can look for heavy bolt lift. On the Semi-auto bolt lift can't be used to assess pressure.

 

[Darryle]

I wonder if you have the bolt/firing pin bushed, will that correct the problem.

I wonder what size firing pin you currently have?

 

[RockyMtnMT]

Having it bushed is well worth it.

 

[Coyote Shadow Tracker]

I have a 30Nosler semi-custom rifle that will crater a Fed 215M primer with loads below book maximums. There is no other indication of pressure at these moderate load levels. I'm assuming that the Rem 700 bolt just has an oversized firing pin hole that causes the cratering.

I've had the bolt bushed on another rifle but I'm wondering if there is a real benefit to doing so. Other than the cosmetics of not getting a cratered primer; is there any real benefit to having the bolt bushed?

Pictures?

 

[Varmint Hunter]

Pictures?

No pictures at the moment because my brass has already been reloaded. Interestingly enough, I'm still working with my original 60 rounds of Nosler brass that was from once fired ammo.

 

[Varmint Hunter]

I wonder if you have the bolt/firing pin bushed, will that correct the problem.

I wonder what size firing pin you currently have?

It is a factory original Rem 700 bolt and firing pin from a 300RUM. Pin size ??

 

[Lou270]

What velocities are you getting? For ex, are you basing "below book max" based on powder charge or velocity as well. I have several rifles that exceed book velocities with lower powder charges. Not uncommon these days with custom chambers and everybody monkeying with saami throat specs.

Lou

 

[dogz]

Are you seeing this with other load combo's or just this one? Have you tried other primers?

Also, my curious George side has to ask but what is the load you're using?

 

[dogz]

Having it bushed is well worth it.

Side note, please explain to me what this process is and what does it do?

Thx

 

[Outlaw6.0]

I'd definitely have it bushed. It's relatively inexpensive & well worth it IMHO. I've had a couple 700's do that & just didn't like it. Good 'ole Remington wore out manufacturing equipment.

GUNSMITHING SERVICES: STRIKER PIN BUSHING: M7, M700, M70(PF AND CRF), ACCURACY INTERNATIONAL, BERGARA, HOWA 1500, & RUGER RPR

A relatively frequent complaint with M700 and Accuracy International actions (and others) are cratered primers with factory made ammunition. The root cause of this is from excessive clearance between the striker and the hole through the bolt face. When fired, the primer cup flows into the void...

www.longriflesinc.com

t

 

[Varmint Hunter]

What velocities are you getting? For ex, are you basing "below book max" based on powder charge or velocity as well. I have several rifles that exceed book velocities with lower powder charges. Not uncommon these days with custom chambers and everybody monkeying with saami throat specs.

Lou

Cratering was noted on many loads but a particularly accurate load (that cratered) was 80gr H1000 with a 180gr Accubond for 2,930 fps from a 26" match barrel.

Nosler cases and Fed215M primers were used. Bullets were loaded .060" off the rifling.

 

[Lou270]

Yep, sounds like a mechanical problem. Could be sloppy firing pin hole. Or possibly a weak firing pin spring or possibly just a lot of primers with soft/thin cups combined with the above. Were all loads with same batch of primers?

Lou

 

[Varmint Hunter]

Yep, sounds like a mechanical problem. Could be sloppy firing pin hole. Or possibly a weak firing pin spring or possibly just a lot of primers with soft/thin cups combined with the above. Were all loads with same batch of primers?

Lou

I believe that they were all from the same brick, but I really don't record things like that. I'll finish one brick and just move to the next.