Originally Posted by
Daryll
Basically yes, it will affect accuracy.
During reloading and firing cycles the neck is compressed and then fireformed out again, so the brass "work hardens".
Eventually it will break, showing up as splits in the neck or shoulder.
Even before that happens, the brass won't size properly, which leads to inconsistant neck tension, and inaccuracy.
If you have, or can find, the means to anneal the brass in the neck and shoulder area (heat it until it just starts to glow), that will remove the "work hardening" and improve the consistency of neck tension.
The top match shooters anneal their brass after each firing...