RCBS Tungsten Coated Neck Sizing Bushing is designed to provide precise bullet tension without case lube, due to its Tungsten Disulfide coating.
It is meant for use exclusively with RCBS Gold Medal Match neck sizing dies and is self-centering for proper case neck alignment.
To select the correct bushing size, subtract .002"-.003" from the loaded cartridge's outside neck diameter or add twice the neck wall thickness to the bullet's diameter and then subtract .002"-.003".