6mm Creedmoor Case Separation

[roc1]

Question I have is I recently bought a 6mm Creedmoor already have 6.5
Both Savages. I FL resized 6.5 to 6mm shot in rifle then went to Redding bushing FL sizing only pushing shoulders back .002-.003 measured Wilson case gage and Hornady comparator. I am having case separation like excessive headspace. Not pushing loads at all haven’t chronograph them yet but loads are midrange. Only had 3 all Hornady brass through whole lot out.
But even Norma cases have ring at base but not like Hornady. Using dental pick I don’t feel ridge in any other cases at all but chunked Hornady anyway. My guess brass is wore out several loading on it. Has been Annealing maybe only 1x. What else would cause it? I am ordering new 6mm Creedmoor brass try that
Thanks in advance
Roc1

 

[Walkalong]

I FL resized 6.5 to 6mm shot in rifle then went to Redding bushing FL sizing only pushing shoulders back .002-.003 measured Wilson case gage and Hornady comparator. I am having case separation like excessive headspace.

You have to be moving the shoulders too far for the chamber. Double check your measurements.

One way to get a good measurement on brass for your chamber is to hammer a couple of cases with near full loads two or three times with lightly lubed cases and then get a measurement of where the shoulder is. They'll be more fully formed to the chamber.

 

[roc1]

Thanks I did double check might need try that method

 

[Nature Boy]

I’d also have a smith check the headspace in your rifle. If it’s excessive it could be causing your premature case failure. A friend recently had this happen with his brand new savage .338L. He was getting case head separation after 3 firings with no warning.

Since its a savage it can be adjusted to proper headspace specs if need be.

 

[roc1]

Yep thought bout that have to buy gages or it lest no go
Have rebarrel savage before

 

[243winxb]

. I FL resized 6.5 to 6mm shot in rifle then went to Redding bushing FL sizing only pushing shoulders back .002-.003 measured

Your sizing process is not clear to me.

Are you using the same Redding fl S bushing die for both 6.5 and 6 mm's? Just with different bushing?

 

[roc1]

No 6mm die for 6mm 6.5 for 6.5

 

[GooseGestapo]

You could be over annealing the brass. Too much, too deep, and you soften the cases to point they fail.
I've had a similar but different issue with reformating .32/20 Starline brass to .218Bee. Annealing did little as factory brass is already fairly brittle.
Hornady, in my experience is only a little less soft than Federal brass.
Don't believe you should anneal till at least after 5-rounds, and then, ONLY the necks...