Culling brass

So I am currently culling a batch of brass. It's probably had 8 firings. With stout loads. There's been the odd separation so it's going under the microscope.
Of the batch of 500 it's looking like 15% aren't going to pass.
I just wanted to put this out there for discussion and information. It's been annealed every firing, it's had a cycle of 2 collet die loads then 1 bump die pass.To allow it to chamber with a two thousandth
bump. So not exactly what I would call overworked it's just near the end of it's useful life.

Attachment 264472

Tell me what you see from this lot.

Is that incipient head separation on most of them - going by the line around the diameter, up from the base a few milimetres?

What calibor & make of brass?

2_3_4_5 all have light colour at web but yeah 3 is "interesting" can't see neck issues.

@flock its .308W but I am not naming the brass, I dont think it matters in this instance. And wouldnt really be the manufacturers fault, its all had a fair amount of pressure in a target rifle.

Ok I still have 80 odd Laupa brass, culled 20 it's done 30+ reloads, also Lee neck collect die only bump when things get sticky to load, annealing more often than I used to these days. Neck turned at about half life, annealed accordingly. Some of my loads are hefty, 308W - 45g 2208 behind 175 targex at slighty over 2700fps. Have never had a case seperation, as yet. The 20 I tossed I thought had loose primer pockets, but in hind sight they weren't that bad.

@johnd. Looksuke chromed brass to me; not that that is normally a problemi, bit I do know one brand of that which is quite light. How much under sized at the shoulder when you started?

@Woody that's just the colour hue from being in the tumbler, it's standard brass not nickel coated.

On that batch of brass when new, how much short of yr 2 thou" shoulder bump was it? 5,10,15,20 thou" ?

No idea @Woody it came as loaded ammo. Wasnt any need to see how big it was untill it went bang.

Right there may be the source of tbe problem.

Are you saying if I had measured it before the first firing I would have not shot it?
I dont follow the path ?

Whats with the longitudinal scratching, does brass balloon in diameter? Does your sizing die need an internal clean?

No 3 looks like its dead. Others look ok.

@Steelo yes the die does look like it needs a clean. The only area that cant be resized is the depth of the shell holder, all in SAAMI spec.
So the lower shinny circumferentual ring is where the die sizes to. And is usually where the case webb starts to tapper out and also where most casese are unsupported just ahead of the extraction groove.