Do I throw away this whole lot of brass?

[Troutslayer2]

I have been messing with some brass that I know is on it's last loading. I have a bunch more of it prepped and ready to load but maybe 10% of them are coming out of the chamber with partial case head separation. Should I have quit using it the first time this happened to a single piece or is ok to run through the rest of of the lot before trashing it? It's been fired 5 times, Nosler brass 280 AI. I am not pushing it that hard and the gun has a tight chamber.

 

[nkyshooter]

hmm ... not hot loads and an ackley chamber makes me think that the headspace might be a bit on the long side (excessive) ... have you checked it?

Are you full length sizing each time? ... and if so, I'd be interested to know how much it is getting set back each time. If headspace is at or near 'minimal' then I'd say this brass maybe shouldn't be used anymore ...

FYI - I've got cases with lots higher number of reloads on them and the case heads are in great shape ... my issues typically begin with split necks (for cartridges in which I am using traditional neck and/or full length sizing methods) ...

 

[DUSTY NOGGIN]

no such thing as partial separation .. scrap it ..

 

[DoneNOut]

Throw away. Ruptured brass in chamber sucks!

 

[Troutslayer2]

Is there a way that my sizing die could be to blame for this?

 

[nkyshooter]

Doubtful ... is there anything that gives you pause or makes you suspcious of the sizing die?

I'm more thinking this is subpar brass or is an excessive headspace issue ...

Do you full length size each time or neck size only?

 

[quigley257]

Looks like you may be bumping the shoulder back too far if thats happening after only 5 loadings.

 

[nksmfamjp]

What is your cbtd new and fired?

 

[Troutslayer2]

Looks like you may be bumping the shoulder back too far if thats happening after only 5 loadings.

I'm bumping the shoulder back .0015, that is definitely not the issue. I wish I had a brand new piece to measure against a fired one. From what I recall, there was not a lot of growth on first firing.

 

[quigley257]

That's bizarre if you're only bumping that much. I have cases with 9 firings that don't show any sign of separation.

 

[Troutslayer2]

Doubtful ... is there anything that gives you pause or makes you suspcious of the sizing die?

I'm more thinking this is subpar brass or is an excessive headspace issue ...

Do you full length size each time or neck size only?

The only thing that gives me pause is that I had the same problem with a different 280AI. The only thing that is the same across both of them is the die, a RCBS SAAMI die. Nothing special but it has produced accurate ammo.

 

[quigley257]

I threw out a batch of Norma 6.5 Creedmoor brass after the 14th loading because I could see and feel the beginning of head separation. Definitely got my moneys worth out of that batch.

 

[jdyoung]

Is there a way that my sizing die could be to blame for this?

Not the die specifically, but the die "setting".

Doubtful ... is there anything that gives you pause or makes you suspcious of the sizing die?

I'm more thinking this is subpar brass or is an excessive headspace issue ...

Do you full length size each time or neck size only?

Looks like you may be bumping the shoulder back too far if thats happening after only 5 loadings.

as nkyshooter and quigley257 advised in #'s 6 &7, it is more likely you are setting' the shoulder back or another way is to say "not letting the cartridge fully fit your chamber".
To use this brass anymore is risking scoring your chamber.

 

[jimbires]

if you're setting up the die on brass that is not fully expanded you're sizing to much . you need to fire the brass and neck size only until the brass gets tight to chamber . then you can set up your die to bump the shoulder on this fully expanded brass .