Sound like you need a taper crimping die. You don't want to roll crimp 45 ACP because the case headspaces on the mouth.
35WN
This ^^^^^^ (in addition to getting enough umph in your loads to consistently run the slide back to slide lock.) Get a taper crimp die and crimp your loads to a specific dimension across the case mouth (without looking, I think I crimp my .45's to .470 or .471, somewhere around there.)
