I am assuming the picture below is a cratering problem. i am loading new winchester 223 brass with 22.5gr ar-comp and 75gr a max at 2.4" oal. I am shooting this out of a 223 AI chambered bolt gun. Can I expect this during fire forming?
- Thread starter poke5353
- Start date
Re: Cratering?
Happened with mine exactly like that when fire forming and none since.
Happened with mine exactly like that when fire forming and none since.
Re: Cratering?
Good to know
Good to know
Re: Cratering?
POKE...FYI, what is happening is that the new case, even tho it is supposed to be head spacing on your new AI chamber, is ever so slightly short...so, the firing pin hits, the case is driven forward, the primer extrudes just a little bit until the pressure drives the case back, re-seats the primer, getting a little "cratering" appearance around the firing pin indentation in the primer, and the whole case expands to fit the new chamber. If you don't bump the fire formed case back too much, you won't see that again. JMHO
POKE...FYI, what is happening is that the new case, even tho it is supposed to be head spacing on your new AI chamber, is ever so slightly short...so, the firing pin hits, the case is driven forward, the primer extrudes just a little bit until the pressure drives the case back, re-seats the primer, getting a little "cratering" appearance around the firing pin indentation in the primer, and the whole case expands to fit the new chamber. If you don't bump the fire formed case back too much, you won't see that again. JMHO
Re: Cratering?
That just looks like what a Rem700 does, to me.
FWIW, I think "cratering" is an over-rated method of determining overpressure. In my experience, Rem700s do just what your picture shows, pretty much regardless of the charge. The Savages I've loaded for seemed like they'd probably blow up before they ever "cratered" a primer - meaning I never ever saw a cratered primer even at times I was straight up OVERpressure.
The exception to this is my FN SPR in 284Win. It's first outwardly apparent sign of pressure is a cratered primer, which will begin to ocurr **just** before a stiff bolt lift is felt.
My advice to you is to "forgetaboutitt" unless:
- You are seeing ejector marks on the casehead
- are getting stiff/heavy bolt lift
- are getting smoked or pierced primers
- are making primers REALLY flat
That just looks like what a Rem700 does, to me.
FWIW, I think "cratering" is an over-rated method of determining overpressure. In my experience, Rem700s do just what your picture shows, pretty much regardless of the charge. The Savages I've loaded for seemed like they'd probably blow up before they ever "cratered" a primer - meaning I never ever saw a cratered primer even at times I was straight up OVERpressure.
The exception to this is my FN SPR in 284Win. It's first outwardly apparent sign of pressure is a cratered primer, which will begin to ocurr **just** before a stiff bolt lift is felt.
My advice to you is to "forgetaboutitt" unless:
- You are seeing ejector marks on the casehead
- are getting stiff/heavy bolt lift
- are getting smoked or pierced primers
- are making primers REALLY flat
Re: Cratering?
I completely agree with Turbo54...I get the same result from my Rem 700 regardless of charge. His 'red flags' are sound advice that will tell you more than the crater.
I completely agree with Turbo54...I get the same result from my Rem 700 regardless of charge. His 'red flags' are sound advice that will tell you more than the crater.
Re: Cratering?
Thanks guys
Thanks guys
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