Pressure Signs, Where To Start

S

Signguy

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Okay guys, I am a newbe.

I decided to chamber my first rifle after reading an article about a 22-6mm.

I have done so and on the first try I had excessive headsapce.
I have since recut the chamber to .0005 headspace. Started fire forming brass and have a slight crater on some 210M primers with 46.0 gr of RE22.
Double checked headspace with a go gauge and am .0005.
Thought it could be fire forming so I shot two more rounds through the gun from fire formed brass, same thing. Have checked all measurements of brass.
No expansion, nothing else except a slight crater around the primer, and I mean slight.

I should add, I did this on a FN Hernstal action which as far as I can tell it is a Win 70.

I don't know where to start
Any help is appreciated.

Signguy
 
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Many times, cratering is more indicative of a loose fit between the firing pin tip and the hole in the bolt face than excessive pressure. I tend to place more faith in bolt lift, the shape of primers' corners, ejector marks, and web expansion measured on the second firing of a case.
 
Signguy said:
Okay guys, I am a newbe.

I decided to chamber my first rifle after reading an article about a 22-6mm.

I have done so and on the first try I had excessive headsapce.
I have since recut the chamber to .0005 headspace. Started fire forming brass and have a slight crater on some 210M primers with 46.0 gr of RE22.
Double checked headspace with a go gauge and am .0005.
Thought it could be fire forming so I shot two more rounds through the gun from fire formed brass, same thing. Have checked all measurements of brass.
No expansion, nothing else except a slight crater around the primer, and I mean slight.

I should add, I did this on a FN Hernstal action which as far as I can tell it is a Win 70.

I don't know where to start
Any help is appreciated.

Signguy
Click to expand...

Why would you start with 46.0 gr of RE22 in a 22-6mm and not expect high pressures and primer cratering or even worse?

Back the load down a couple of grains and if the primer cratering goes away, than you know that you were entering the area of max load for your particular barrel and bullet combination.

What bullet/gr. are you shooting?....................Don
 
Hi Don,

On the first chamber with a headspace problem I started with 44 gr of RE22 and had the same issues with the primers but the cases did not form very well.
I am shooting Hornady 75gr A Max. Lija 1 in 8 twist barrel.
 
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I think you will get cratering from a weak firing pin spring and from a poor fit of the pin and hole more often that from pressure.... and there should be other pressure signs first. The old "harder to lift bolt" is one of the best pressure signs on mass produced actions.

Recently I had a 700 in an Ultra Mag with what appears to be a slight bevel to the firing pin hole and the fired primers look ugly. They had not leaked but I told the fellow to contact a Remington warranty depot. He did and described it well to them and said a gunsmith had inspected it and said the poor fit should be corrected. The Remington warranty guy said that "small bevel" is deliberate and Remington considers it correct. Personally he did not agree but unless primers were rupturing/leaking (some incorrectly refer to that as a "pierced" primer) Remington will do nothing.


.
 
Signguy said:
Okay guys, I am a newbe.

I decided to chamber my first rifle after reading an article about a 22-6mm.

I don't know where to start
Any help is appreciated.

Signguy
Click to expand...

The cartridge you are loading is a 22-6mm what?? i.e. what is the parent case?
 
I had a 223 that produced craters jagged enough to draw blood and the odd puncture. Everyone said "pressure". Pin protrusion was too short and a weak spring. Fixed them both and the problem was totally gone, and the gun started to shoot well which it had never done.
 
Thanks for the input guys.

Dennis, there are no other signs of pressure other than this "crater" problem.
I will look into the spring and firing pin. Thanks.

JerrySharrett, The parent case is a 6mm Remington.

I am curious about the action though. Is it this one type of action or all "commercial" type actions?

Thanks again for all of your input guys.
Signguy
 
Signguy said:
Thanks for the input guys.


I am curious about the action though. Is it this one type of action or all "commercial" type actions?

Thanks again for all of your input guys.
Signguy
Click to expand...
Some few commercial actions are rated in the 60,000-65,000 PSI range. Most modern actions suggest staying in the 48,000-55,000 range.

But, any time you get into the 52,000+ range you better be darn sure you know what you are doing. Playing in that range can get you hurt bad...or worse.
 
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