Prepped some .308 cases for my new bolt gun. I have RCBS full length dies. My Speer manual has a photo showing the FL die adjusted with a small gap between the shell holder and die. The caption states: sizer die set for neck-sizing(gap between die and shell holder). This results in no "Camming action" when at the top of the stroke. I tried it and it left an unsized portion of the neck just above the shoulder. I went ahead and adjusted it per the die instructions and ran my brass through it. The case are now FL sized. Can the FL dies be used to neck size only? I'd rather not buy a separate neck sizing only die if I don't have to.