Whether it's a hunting gun, an accuracy rig or anything in between.....seeing improvements with neck sizing (over full length sizing) is really pointing out issues with the full length die itself, press issues, die adjustment issues, shell holder issues, expander issues, etc.
You really can't say for sure unless you look at each step in the full length sizing operation. 90% of the problems I see are with die adjustment and expanders. It's pretty rare to actually have a 'bad die' issue if the die is from a quality manufacturer.
There's a few Lee dies here. Best paper weights ever.
-Al
