REDDING NECK SIZING BUSHINGS Redding Neck Sizing Bushings have external dimensions 1/2"" O.D. x 3/8"" long and freely interchange in all Redding Bushing Style Sizing Dies. They are available in .001"" size increments throughout the range of .185"" through .368"", covering all calibers from .17 to .338 and clearly marked with size identification.By selecting the correct bushing, you are now able to provide just the right amount of neck tension to properly hold the bullet without excessive resizing.To determine proper Bushing size, measure the outside neck diameter of a loaded cartridge with a precision micrometer, then subtract .001"" to .002"", to allow for brass spring back and bullet tension.FEATURES:- Heat treated steel;- The sizing diameters are hand-polished with a surface hardness of Rc 60-62 to reduce sizing effort.REDDING RELOADING EQUIPMENT:For nearly 80 years Redding Reloading has been at the forefront of the Reloading Equipment marketplace. With innovative and high-quality products, Redding Reloading is committed to providing gun owners with the utmost in dies and accessories. Thanks to an ever evolving and growing market, Redding is sure to have the perfect presses and accessories for your particular gun make, model, and design.