Redding Neck Sizing Bushings are available in two styles. Both share the same external dimensions (1/2” O.D. X 3/8” long) and freely interchange in all Redding Bushing style Neck Sizing Dies. They are available in .001” size increments throughout the range of 185” thru .368”, Covering all calibers from .17 to .338 and clearly marked with size I.D. By selecting the correct bushing, you are no able to provide just the right amount of neck tension to properly hold the bullet without excessive resizing. Heat treated steel as above with the addition of a Titanium Nitride surface treatment to further increase the effective surface hardness and reduce sizing friction.