RCBS Tungsten Coated Neck Sizing Bushings provide precise bullet tension without needing traditional case lube, thanks to their Tungsten Disulfide coating.
They are designed for use with RCBS Gold Medal Match neck sizing dies and should be selected based on neck diameter for optimal alignment and tension.
RCBS recommends having a range of bushing sizes around your target diameter for best results, and suggests two methods for selecting the correct bushing size.