Die click story: I have a Varibase die that has interchangeable base bushings that have almost no chamfer. My shell holder has been shortened by about .013. I had a test case that developed a definite click. Seeing that I had a gap between the shell holder and the bottom of the die, with my die set for the correct bump, I took a chance and unscrewed the base bushing to the point where it just touched the shell holder at the top of the sizing stroke, with a case being sized in place. With the additional reach down the case, the click disappeared, and did not come back after firing.
If you look at a typical FL die there is a huge chamfer/radius at the bottom which limits the die's reach down the case. If the chamber makes contact farther down the case than the die does, you have an area that is not sized. Typically guys use a smaller base die that pulls down the part next to this band far enough that it reduces the unreached area. IMO this is not the best approach. If we work with a faster powder and chamber short, trimming the die, we can do away with the excess chamfer, and improve the coverage of the die relative to the chamber, or perhaps just order a truly custom die that has almost no chamfer.