On a lead 200gr SWC, taper crimp about .02 to .03 back of the shoulder. On a lead roundnose, taper crimp at the top of the driving band, just behind the ogive. Actually, a 230 roundnose should seat to the overall length suggesten in the lopading manuals, to match hardball, for proper magazine fot. Set the lenth and taper crimp. A heavy roll crimp will lose your headspace.