Target shooters have found, in general, the use of separate seating and crimping steps produces superior accuracy. But generalizations are just that, and there is no guarantee they will be applicable in any particular case. If you have a bullet design with a crimp groove in it, you should be able to time a single die to seat and crimp without shaving. All it requires is that you have a good case mouth chamfer, burnished smooth by the expander, and the case mouth be passing over the crimp groove during crimping.
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