I use the heavy crimp FCD that ca=me with my 454 Casull die set for heavy 45LC's . Had too in my SRH 454 cause I had some jump the crimp in heavy loads - not a fun time. In my current 45LC RH I haven't shot anything that heavy. Found no need for such abuse! As a Lee 300gr over 14.5 gr of 2400 at 950ish FPS does anything I need done. I save the heavy loads for the 454 '92 Puma!