Has annealing SIGNIFICANTLY improved anyone's accuracy? I am asking this because I don't want to ruin brass to save brass, but if it tighten up my groups, well all bets are off then. Thanks
As the neck of a piece of brass work hardens it will loose neck tension. After resizing you will be able to seat a bullet with just one finger and your thumb when a case neck is really hardened. You will also be able to pull it back out with one finger and a thumb or jar it further down in the case. So, when bullets are this loose in the neck it is unlikely that you can maintain any reasonable standard of accuracy.
If you opt to go to a smaller neck die to get more tension rather than annealing there will come a point in time that the neck has hardened enough that it will split on firing.
Annealing will not improve "new" unfired brass, it is for work hardened necks.
So here are your options:
1. Anneal your brass when the necks get hardened (maybe every four or five firings) and spend maybe $10 on the equipment and process.
2. Keep buying smaller and smaller neck sizing bushing until you split the case necks and ruin it all which will cost you about $200 in bushings and ruined brass.
3. Every four or five firings just throw all your brass away and buy new brass which will cost you maybe $150 plus all the time for brass prep.
Its your money and your time.