RCBS Tungsten Coated Neck Bushings provide precise bullet tension without needing traditional case lube, due to their Tungsten Disulfide coating.
They are designed to be used exclusively with RCBS Gold Medal Match neck sizing dies and are self-centering for proper alignment.
To select the correct bushing size, subtract .002"-.003" from the loaded cartridge's outside neck diameter or calculate based on neck wall thickness and bullet diameter.