I'm not sure about the Redding FL die but from what I looked up, the set you have comes with both a "standard" die with an expander ball, and a bushing die. Since you didn't use the bushing die, I figure you used the expander ball die. In any event, I have a Forster FL die that uses an expander ball, it's really important to properly align the ball vertically inside the die so that the full neck is compressed, then the ball expands it on the way out. I could see that if the ball is out of position, it may result in the neck being compressed into the ball on the downstroke.