(Also a Ron Power
suggestion.) Removable brass pilots precisely center breech end of
Chamfer Tool Extension Rod to eliminate any possibility of cutter
runout. Do not interfere with cutting action or chip removal. Four
sizes: .38 (.346"), .38-40 (.394"), .40/10mm (.388"), .41 (.398"), .44 (.416"), .45 (.442"), .475/.480 (.466").
Big Book Catalog, Issue:65, Page:497
New Product Supplement, Issue:581, Page:012