The L.E. Wilson, Inc. Steel Neck Sizer Die Bushing is made of hardened stainless steel and comes in .001” increments with a .003” taper.
This bushing allows for tighter sizing by flipping it over, with markings facing down, which is useful for hardened brass or fine-tuning neck tension.
To select the correct bushing size, subtract .002" to .003" from the loaded cartridge's outside neck diameter or calculate based on case neck wall thickness and bullet diameter.