Case head seperation or chamber marks.

[rrflyer]

I'm tryin to figure out some rifle problems.

Brass is new winchester 243 brass from same lot as old.
Necked up on Forster full length die
then neck turned to clean up about 70% of the necks.

Load was 42.5gns at 2.78coal which puts me about .02 off the lands.

Previous chrono from earlier batch of brass showed this to be doin 2850FPS

Load was dispensed with a chargemaster and double checked on my gempro 250.

Brass headspace grew .002 to .003 on this initial firing.

Rifle shot 1/2 moa with this load

Barrel has about 600 rounds through it and was cleaned before being shot.

Anybody else seeing a problem or am I over thinking things.

 

[SONIC SAAMI]

You are fine, from what I have been told Winchester has been making the brass smaller at the base.

PM Chad of Long Rifles Inc he has some info on this.

 

[milo 2.0]

Were the five in bottom pic sized? Looks like die markings here. If they weren't sized, the chamber could use a quick polish job.

 

[bh-ltr]

Bend a paper clip straight with a short 90 degree bend at one end. Then use this as a feeler. If you are getting case incipient case head separation you will be able to feel a slight indentation where that line is on the inside of the case. You'll actually be able to feel the thin spot in the brass. To me that looks like a sizing die mark. I've got similar marks on my brass and was a bit worried about them. Not seeing any extractor marks or flattened primers and those look like they might be Federal primers which I found to have a pretty soft case. When switching to Remington primers and matching the velocities I had no issues with primers flattening and the same marks. But couldn't feel any thin spots in the brass. I think you're fine.

~Brett

 

[427Cobra]

My Win brass looks the same, your GTG

 

[Jeffvn]

Looks like die sizing marks to me. My custom dies leave similar looking marks ....

This is early case head separation:

 

[Fuzzball]

I see nothing but the normal expansion where the brass head and web gets thin enough on the side wall for the pressure to push it against the chamber.

 

[thrusty]

+1...Looks like die sizing marks to me. I have them as well from Redding dies.

Early signs of case head separation is more pronounced like something has cut into it.

 

[Turd in the Pool]

I don't like the looks of the primer flowing around the firing pin. They don't look flat so I would clean and lube your bolt and see if that helps.

 

[turbo54]

Nothing to worry about. Looks like the chamber could benefit from a little polishing, but if it is extracting spent cases nicely, it isn't necessary.

I don't like the looks of the primer flowing around the firing pin. They don't look flat so I would clean and lube your bolt and see if that helps.

The ring/ridge around the primer indent looks like every Remington I've ever seen that hasn't had the firing pin hole in the bolt bushed.

 

[rrflyer]

The fired cases haven't not been sized.... That's straight out of the chamber.

 

[wchartz]

This is definitely not case head separation. A case head separation shows up as a slightly irregular ring approximately 3/8" above the head. The reason it is irregular is that the brass is not of uniform thickness at any one set distance above the head therefore the stretch mark varies in distance above the head. It first shows as a bright line then just before letting go you will see a dark line in the stretch mark which is carbon from escaping gas.

 

[SporterII]

I bet the expansion at the 'ring' will be about .005". Win brass is a tad small there. Not by much though. Measured against an unfired case and then against other brands. Norma probably .0015 bigger.
I saw this in mine and did sweat at first. Mine is fine at .005".
ETA;
I cut some open, thats how I figure its fine. You can do the same thing and see for yourself.