amlevin said:
I use a Lee Collet die for all my neck sizing. Clean cases stay clean, no lube anywhere after sizing. Also less work hardening. No more undersizing of the neck first then running an expander through it to bring it back to the correct size.
amlevin, Every time you use a Lee Collet Die, or a die that only neck sizes, you're producing a cartridge/case that never returns to its original designed dimensions until full length sized. The more often you fire it, without full length sizing, the more often you're producing a case that continually differs from it predecessor, until such time that it can no longer be chambered.
Full length sizing, each and every time you re-size, preserves the original dimension without overworking the brass. It's the
lack of frequency that leads to overworking and case hardening.
The more often you return to the original dimensions, done in minute or very small proportions, .0005" to .001" or to minimum SAAMI specs [Redding dies come to mind], the less work or force is needed.