The Gold Medal Match Series comprises the finest reloading dies built by RCBS®. The two-die Full-Length Neck Bushing set includes the Full-Length Neck Bushing Sizer Die and a Seater Die. The sizer uses a self-centering changeable neck bushing to let reloaders precisely set the amount of tension on the bullet. This reduces work-hardening of the case neck brass, prolonging case life and increasing accuracy. However, getting these benefits requires the use of high-end brass with consistent neck thicknesses. By removing the neck bushing, the Full Length sizing die can also be used as a bump die to set headspace back the desired amount. Neck bushings (sold separately) are available in .001-inch increments from .189-inch to .365-inch. Note: Neck Bushings are not included.