At least for me, its time for the recycle bin if :
1- if you are splitting case necks'
2 - primer pockets don't hold primers
3 - ghost ring on case (above the sizing ring) telling me that head separation is coming.
4 - spot thinning on case necks that are more than 0.00025 to 0.00050 below nominal neck thickness
1) since I began annealing I have not seen number #1;
2) I don't run max pressure and have never seen #2 except with some early load development brass;
3) when I see about 20-25% of my current lot starting to show a ghost ring the whole lot goes into the bin. I start to see this on 7WSM brass in the 10 firings and above zone. I push the shoulder back 1/2 thou to 1.0 thou each sizing.
4) when I see about 20-25% of my current lot fitting this description the whole lot goes into the bin. Thinning tends to start showing up for my 7WSM brass after 10-15 firings or above zone.
With my 6x47 brass I have yet to see any neck thinning, but that is a tight but no turn neck. I don't konw if it makkes a difference, but its what I see happening.