L.E. Wilson Neck Sizing Die Bushing .312 Steel (B-312)

Description

The L.E. Wilson Neck Sizing Die Bushing in .312 is the interchangeable insert that lets you take real control over how tight your case necks grip the bullet. It drops into a Wilson neck sizer die or a Wilson bushing-type full-length sizing die and sizes the outside of the case neck to .312 inch. Machined from heat-treated steel, it holds its dimension cycle after cycle, which is exactly what you want when you're chasing repeatable neck tension across a batch of brass.

The real advantage here is flexibility. Instead of relying on a one-size expander ball that stretches and pulls the neck every time, you pick a bushing that matches your exact brass and bullet combo. That means better neck concentricity, less working of the brass, and longer case life. If you run different brass lots or load more than one cartridge, keeping a few bushings on the bench lets you tune each one without ever touching the die body.

Picking the Right .312 Wilson Bushing

Sizing is simple. Measure the outside diameter of a loaded round at the neck where the bullet sits, then subtract .002 to .003 inch to account for brass spring-back and the grip you want on the bullet. You can also work it from neck wall thickness: multiply the wall thickness by two, add your bullet diameter, then subtract .002 to .003. Either way gets you to the bushing that leaves roughly .001 to .002 inch of tension, which is the sweet spot a lot of precision handloaders aim for.

How the .312 Neck Sizing Bushing Fits Your Setup

These steel bushings freely interchange in all Wilson bushing-type dies, and they'll also drop into Redding, Hornady, and RCBS bushing dies. They do not fit Forster or Whidden dies. One quick tip from the bench: these are steel, so a little case neck lube keeps things smooth and leaves clean necks behind. Made in the U.S.A., sold as a single bushing, with the die body sold separately.