A crimp can & will destroy the accuracy of a lead bullet by distorting the bullet when applying the crimp.
If you feel you must crimp, several Shooters have successfully utilized a form of taper crimp.
First remove the de-capping stem from the full-length sizing die & place the round in the shell holder. Move the ram to the top of the stroke. Slowly screw the die onto the loaded case & lock in place w/ the desired amt of taper crimp. If done w/ care, this will apply a slight taper crimp to the loaded round.