Redding 0.351 Type S Bushing TiN Coated Bushing fits Redding Competition and S-type sizer dies. Titanium Nitride (TiN) coating adds durability and lubricity. The sizing diameters are hand-polished with a surface hardness of Rc 60-62 to reduce sizing effort. To determine your bushing size, measure the outside diameter of your cartridge neck with a bullet seated. Subtract .001" from that measurement to get your bushing size.