In my research of the Lee FCD, it says it is capable of a light taper crimp, to a hard roll crimp. On my 223, I have a loaded round in the shell holder, ram all the way up and screw in the FCD until it touches. Then lower the ram, screw in the FCD in a little (1/4 turn) and go from there. Belly could probably do the same, increment the FCD in by 1/8 rev turns or something and he might find the sweet spot for his rifle.