Primer pockets will also tell a story, are the loose or getting loose.
How much powder did you load the cases up with. was it a hot load.
It varies as was said above me, and keeping count means using the same brass until failure. Be that number 500, 100 or 20 pieces. I generally used 30 pieces of brass which means I have a pretty good supply that is primed and ready.
I also agree with what was said - 8 or possibly 12 times. then they are off to the trash if they are showing signs of fatigue or not.
Now, 5.56 / 223 is a different animal. I can pick that stuff up off the ground, get it home, clean it, size and prime, load some powder and a bullet, go shoot.