Thread: Cratered Primer

Was tighter on the other side

Originally Posted by Marty Henry

There seems to be a lot of clearance around that firing pin either that or its an optical illusion

A generous clearance. Can be cured by a gunsmith if the gunsmith diagnoses that there is an illness in the first place. What do you think @gundoc?

Yep, piss poor firing pin fit in bolt face. It can only be cured by replacing or rebuilding the pin. It is a specialized job to get the correct fit, shape and protrusion. A mistake with any one of those three criteria can cause safety issues.

Greetings Again Charliehorse,
I thought I might lighten the tone a little by making a few suggestions that may work around the problems you are having. The photo of the bolt face does appear to show a loose firing pin hole and I think I can see a fraze (a slightly raised ragged edge) around the plunger ejector hole. This fraze is likely the reason for the round stamp like marks on the case heads. Together with neck sizing this is likely also responsible for the small polished areas. Removing the fraze should eliminate or reduce both problems. You are likely to get polish marks on the case heads on the second or third firing with neck sizing together with tight chambering. Careful minimal full length sizing should then restore normal function. As far as the cratering goes switching to a primer with a harder cup may reduce the problem to tolerable levels. I have used Federal primers exclusively for some years and have seldom had any problems with cratering even with max loads. See if you can cadge a few primers of different types of your mates to try. Definitely worth a crack before doing anything major. You should be using large rifle standard primers in the .22-250.
Regards and Best of Luck Grandpamac.

@grandpamac in regard to minimal FL sizing should I even go there with only feel and calipers? The fact I'm asking probably answers my own question.
In your guide you talked us through adjusting the FL die but I struggled to notice the difference through the adjustments.

Greetings Charliehorse,
I now remember that in one of your early posts you mentioned that even factory rounds chamber snug. This would mean that you have a minimum chamber and also dies that do not oversize the case. Congratulations, it does not happen all that often. Looks like you have gone through the process well and proved that this is what you have.
Regards Grandpamac.

Yea maybe or maybe not, was tending more to me not being able to tell, a very good chance I have stumbled all the way to here, I don't think I should be full length sizing until I actually know how far to go

Greetings Again,
There is one thing that you can look out for which would indicate an over sized case. If you load and fire some of your full length sized cases with the same load and compare the outer edge of the primer you my find that the corner to the primer to the full length sized case is a little sharper than that to the neck sized one. It may even be riveted a little where the primer has a sharp edge at the corner like the brim of a hat. If there is a minor change and definitely no riveting your head space and full length sizing is not excessive.
These changes are often mistaken for high pressure by primer readers when they are just head space. I will try and do some photos with my new camera after I have finished my wood shed floor in a day or two.
Regards Grandpamac.