I have crimped cast .45ACP using Precision Bullets. These are lead bullets covered with a black, slick "plastic" coating. I have also crimped 10mm jacketed, using my Lee FDC roll crimp for both types. I used one full turn after making contact with the bullet. I tried to back off to 3/4 on the jacketed, but my Glock wouldn't go into battery. I had to bump the rear of the slide with my thumb to engage. The Precision Bullets cast worked fine and gave good groups.
I read just recently that crimping TOO tight on cast can cause an "undercrimp" in that the brass will snap back but the lead will not.