worn out bottleneck cases?

[SJan]

What are things to look for to tell if cases have reached the end of their useful life?

Obviously any cracks, distorted or loose primer pockets are easy to find. I'm sure there are many variables involved, so please state your methods and some reasoning behind it.

Specifically talking about bottleneck rifle cases

 

[Fixxah]

Primer pocket empty after firing, that case is in the scrap bucket. If there were dents that were fired out then look there for stress cracks on the brass. I usually toss them but have marked cases to see if they gave way at the dents and in most instances this has proven to be true judging by the dull brass in that area after cleaning. YMMV

 

[Slowdive]

I load bottleneck cartridges in lots (except .223). If I see a few neck cracks or loose primer pockets, I scrap the lot.

For .223, I just cherry pick the damaged necks and loose primer pockets. The reason I do this for .223, is that its such a popular round...it's hard to be sure that the brass I pick up is mine. I could mark them, but its another step. It's the one bottleneck I load in bulk.

 

[Finalygotabeltfed]

The shiney "ring of doom" just above the web after resizing.
This is an indicator of stretching and thinning of the case wall. This is usually accompanied by a thickening of the metal in the neck wall as the brass migrates forward when fired. Using cases that exhibit this shiney ring is risky in a semiauto as you can have a casehead separation and do damage to you or the gun or both, to include death.
Any good reloading manual should include the method of checking the case wall internally by bending a 90 degree hook on the end of a piece of wire and sharpening the end a little and using it as a probe to find the ridge that is formed inside as the brass begins to fracture. It presents itself as a rough spot or ridge as you drag the tool in and out of the case agains the sidewall.

If you find a case that presents this indication, look inside with a good light and see if its fracturing. If there is ANY reservations, toss the brass its not worth the risk involved.
Read and understand the mechanical forces involved in ammunition and their indicators.