Case head seperation problem

[RL338]

I would say you have a loose chamber and using a small base sizing die.
What type of rifle were these shot in and what die set are you using?

 

[sako2]

The mark on the first 2 pictures looks higher on the case. What lube are you using?

 

[sgish7]

I’m using all RCBS equipment

 

[sgish7]

I

I would say you have a loose chamber and using a small base sizing die.
What type of rifle were these shot in and what die set are you using?

have many different AR’s and they could have come from any of them. Most likely it came from my Daniel defense or my colt

 

[RL338]

I

have many different AR’s and they could have come from any of them. Most likely it came from my Daniel defense or my colt

I was kinda thinking the brass was fired out of a MSR chamber. To make things easier down the road I would suggest keeping brass separated between rifles.

 

[hunter24605]

Some of them just look like where the die stopped sizing at the head. Some look like potential separation or the die was set too high. Are they standard dies or small base. Have you mic’d the head? My 280 Ackley brass leaves a “shiny” area at the head, but it doesn’t have a ridge or step in the brass and it measures up fine. I would measure the head, and run a dental pic inside, but I think you’ll find they are ok.

 

[ElmerThud]

When I read this the first thing I’m thinking is under lubed cases that the rim is being pulled off in the shell holder. Pictures would be helpful in this situation.

This is a possibility, though personally, I've never come across it before.