Do yourself a favor and buy a Redding Profile Crimp die. Nice final crimp. I use mixed brass and have never had a problem but I use 200 grain soft lead bullets that are BP lubed and sized to .427 so they will chamber in my Colts. A 2.2cc dipper of Goex or other BP, seat and crimp a bullet and let 'er rip! This load works well in my Colts and my Uberti '73. Also does just fine in my two original 73's. I have been a cowboy action shooter for 18 years and started with .45's loaded with BP. I switched to .44-40 about 7 years ago and curse myself regularly for not starting out with that caliber.