I searched, holy mother, lots of strong words! For simplicity let's keep this about the brass; accuracy seems hotly debated, but mine is practice/hunting ammo, not competition. In the interest of clarity I'll describe what I think is happening and then... So partial f/l sizing (bumping the shoulder) sizes the neck down and expands it out again, while putting the shoulder back into spec for YOUR RIFLE'S CHAMBER ONLY if you adjust it down little by little until it just chambers without "undue" force. Collet neck sizing squeezes the neck down on a mandrel working it once per reloading cycle. I understand the desire to avoid sizing the brass to min spec and then stretching it back to the length of your rifle's chamber every time it's fired. Case head separation is the most common brass failure, so avoiding it makes sense. The only thing collet avoids vs "shoulder bumping" is working the neck a bit more, does that affect how often annealing is required to maintain neck tension? Even with lubed brass my f/l dies "pull" pretty hard when withdrawing the expander, but of course chamber pressures are much stronger. In conclusion, for longest brass life, collet sizing until the brass is too tight while chambering, then minimum partial f/l sizing to your rifle's chamber, then repeat the cycle. Have I described this correctly?


















































