I use the crimp option on an RCBS AR15 seater die. It is a taper crimp that has the roll crimp at the end of a longer taper just incase your case length is not consistant. (Supposedly) It seems to work better with fewer crushed shoulders than a standard die with a roll crimp. But, to be consistent, you need to get your cases as close to the same lenght as you can. I have also used a Lee crimp die and that works well as long as you are not power crimping them. They are nice when your cases are not consistently the same lenght.

kwg

For liberals and anarchists, power and control is opium, selling envy is the fastest and easiest way to get it. TRR. American conservative. Never trust a white liberal. Malcom X Current NRA member.