Designed to properly fit new and resized case necks, these pilot stops feature a very unique shape. Slightly undercut, this shape will not pick up imperfections at the case mouth or neck/shoulder junction resulting in smooth accurate indicator readings when used with the new Case Neck Gauge. Two sizes are available because of the small (9/64”) mandrels used for .17 & .20 cal. and small flash holes. The larger size (for standard 3/16” mandrels) work equally well with the tools of other manufacturers.