What's the purpose of and/or the reason for the grooved case?

Excessive headspace of the rifle's chamber, or excessive setting back of the case shoulder during resizing operations, most likely caused this problem.

If you have a Stony Point or Hornady case length gauge that measures the case from the median point (about the middle) of the case shoulder to the base, use it to measure the case length (to the shoulder, not the overall case length) of:

1. Factory ammo.
2. Cases after they have been fired in your rifle.
3. Case length after resizing.

After firing, the case shoulder only needs to be set back .002-.003" from that of the fired case. Any more, and the case stretches excessively each time upon firing, thereby drastically shortening case life.

There are many ways to attack this problem:

1. Use a set of Redding Competition Shell Holders to adjust the amount of shoulder set back that occurs when resizing.

2. Have a custom resizing die made, but know that such a die is only good for a particular rifle.

3. Have the rifle's headspace measured/adjusted to diminish the excessive headspace, if that is indeed the problem.

I've had this problem, expecially with .223 brass I use in CMP National Match Course matches. After having several case head separations, I attacked and solved the problem.

Hope this helps,
Bill.

I guess I wasn't clear, this is new factory ammo.

Good question. It is a brass plated steel case and Berdan primed.

Thats weird

The guy I got this from was shooting it in a brand new Savage. It shot just as well as the Federal and Remington he also tried. The fired brass was perfectly formed to the chamber.

Its shoot once and throw away case stuff

Golden Bear cartridges are made in Russia and are non corrosive, Berdan-primed, and brass plated. This is .30/06 Soft Point 168 grain bullet with brass plated steel case, bimetal, 20 round box. A case would be 25 boxes. We sell this by the 20 round box

That's the stuff.

But still, what is the purpose of the groove?

I would like to know the purpose from someone in the know and not just an opinion such as I am offering up.

The Russians 22LR match ammo for International competition was the first to used dimpled cases. Their ammo was top notch. On the 22LR it was like a pressure spike buffer.

Federal copied that in their old Gold Medal Ultamatch (long gone) and the US won some Olympic Gold with it (Launi Mehlei) and Silver (Bob Foth).

I am wondering if this is also a pressure spike buffer as well?

quote:

But still, what is the purpose of the groove?

Is it possible the case would collapse , if resizing were to be attempted ?.

I can't think of any reason why a roll grove would be necessary other than weaken the case

after it's initial firing ,so as to prevent reusing said case !. That's the best I've got !!!.

I just ran a fired case thru an FL sizer, no problem.

Sectioned case: