Primer Cratering

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regulate34

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Ok so I started loading for my 30-06. I am getting primer cratering.
I don't belive its from high pressure as it happens from starting loads all the way max loads.
dose not seam to get worse with a heavy charge.
No other pressure signs
Had the head space checked. its fine.
Read on the internet about the firing pin hole being slightly over sized and that if its not puncturing the primer not to worry.

what do you guys think
 
What make of rifle is it and what is your load ?
Are you neck sizing or full length ?
My 30-06 with a 165 gr. bullet and about mid-range powder charge will crater primers with full length sized brass, but not so with neck sized brass and the same load, however the neck sized loads require fair effort to chamber.
 
Kevan said:
What make of rifle is it and what is your load ?
Are you neck sizing or full length ?
My 30-06 with a 165 gr. bullet and about mid-range powder charge will crater primers with full length sized brass, but not so with neck sized brass and the same load, however the neck sized loads require fair effort to chamber.
Click to expand...
Parkerhale/Midland 30-06
H4350 55g-59g
CCI LR primers.
165g Interbonds
FL sized hornday brass
 
Your loads are within reason so if there are no other pressure signs I don't think I'd be too concerned.
If I remember correctly my Parker Hale 30-06 cratered primers come to think of it.
My Grandson has it now.... I'll check with him and see what he loads and if he has noticed what it does now.
 
Did a quick snoop through my load notes and one rifle I have that craters primers is due mainly to a loose firing pin hole in the bolt, possibly your problem.
Another possible cause is a soft cup on the primers you are using and I have found that Federal primers seem to have a softer cup.

It will be interesting to know what you find out... keep us posted ?
 
just pulled the bolt apart.
found the set bolt for the firing pin shaft had come loose. making the firing pin slightly longer.
I am assuming this is the issue.
I guess ill see next shooting session
 
not super impressed.
have developed some loads getting around 1 1/4"-1 1/2"
Its a hunting rig so its plenty for what I hunt.
My goal is to get 1" and ill stop playing with loads.
just got some interlocks to try.
 
Most 98 actions will crater primers in my experience, they are machined oversize intentionally from the military specs on this action. It is nothing to worry about, but if it does become a problem the fix is to bush the pin hole and can be done by a competent smith. Sometimes a weak firing pin spring can allow cratering as the pressure pushes the pin back in the hole and allows the primer to slightly extrude into the pin hole.
 
regulate34 said:
not super impressed.
have developed some loads getting around 1 1/4"-1 1/2"
Its a hunting rig so its plenty for what I hunt.
My goal is to get 1" and ill stop playing with loads.
just got some interlocks to try.
Click to expand...

Thats better then they shot for me. Interlocks shoot really good for me and are dirt cheap compared to inter bonds
 
I have seen newer CF rifles with chamfered firing pin hole in bolt face. Apparently a new idea to prevent primer perforations? These cause the primer to back up into fp hole. Some of newer handguns leave strange primer marks, ie glock, P85 ruger. I don't worry any more, but always check for primer perforation which can cause serious breech face damage(like an oxy-acetylene torch burning small holes). I've seen it on .357 Max, 40 s&w, and .50 bmg. be well
 
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