Everybody offers dies for doing a taper crimp in a separate station.....which is where it should be done. Some makers offer seating dies with taper crimps, some with roll crimps. Older Hornady seating dies for autoloading cartridges used to incorporated a roll crimp, newer Hornady seating dies incorporate a taper crimp. Lee offers seating dies with what they call a modified roll crimp which they say you can adjust to just do a taper crimp.
My opinion, (and most reloading manuals would agree) is that a taper crimp should always be done separately from bullet seating. Roll crimping can be done in the seating step, but only if the bullet has a crimp groove, or you are crimping over the shoulder such as with a 38 wadcutter.
