The cartridge case is supported and aligned with the sizing bushing prior to the sizing process. The sizing process begins, and the cartridge case remains supported in the sliding sleeve as it moves upward. Meanwhile, the resizing bushing self-centers on the case neck. The decapping rod remains aligned by using the die's internal parts as a linear support. The micrometer adjustment of the bushing positive secures precise control to the desired amount. This 6mm Rem Imp 40 Redding Reloading Competition Bushing Neck Sizing Die Set was built for attaining competition shooter precision.