Hardened stainless steel neck bushing from L.E. Wilson. Wilson makes their bushings in .001” increments. The size marked on them refers to the middle of the bushing, which is reamed with a .003” taper. Since the case neck only reaches the middle, a slightly tighter sizing can be achieved by turning the bushing over, with the markings facing toward the case (markings facing down). This is mainly an emergency step to be taken if the brass has hardened, springing back more, and will no longer hold the bullet; or for fine-tuning the sizing to provide less additional “squeeze” than using the next smaller bushing in the normal way. Made to similar specs to the Redding neck bushings. Will not interchange with Forster or RCBS dies.
Brownells Gun Tech™ Tip: There are two ways to select the steel neck bushings you need: (1) Measure the outside neck diameter of your loaded cartridge and subtract .002" to .003". This allows approximately .001" of brass to spring back for correct neck tension. (2) You can also measure the neck wall thickness of your case, multiply by two, add the diameter of your bullet and subtract .002" to .003".
Steel Neck Sizer Die Bushing .309