Well said sirThe issue of how long is based on how much you size the brass and how hot you load them.
Some anneal every time they fire them so the bullet grip is consistently the same. This method
prevents any shift in POI. If your yardage is held to 2 or 300 yards it will be hard to see much difference in impacts. normally the Human factor is the difference.
I prefer to do this on the long range rifle cartridges and anneal every second or third firing on the less intense cartridges, or when one throws a flier. Fliers are normally shooter error unless you call a great shot and it goes out of the group anyway. Annealing and neck turning tends to eliminate this by improving the consistency of the bullet grip ,and this helps in accuracy. (Especially at long ranges.)
If you are happy with 1 MOA accuracy, much of this is not necessary. if you want or need 1/2 MOA accuracy, then it helps but if you want 1/4 MOA or less I feel it is a must.
Case prep is an evolutionary process that takes time and patients and is developed over time as the shooter gets better and demands better accuracy. So carry these process as far as you need or want, then relax and enjoy.
J E CUSTOM