These Full Length Sizer Dies use precision-machined neck bushings (sold separately) to size the case neck just enough provide the exact amount of bullet tension without overworking the brass. To determine the proper neck bushing size, measure the outside neck diameter of a loaded cartridge and subtract .002" to .003" to allow for a small amount of brass spring back. By removing the neck bushing, the Full Length sizing die can be used as a "bump" die to set headspace back the desired amount without disturbing the case neck. Shellholder sold separately.
- Gold Medal Match sizing dies use a separate neck bushing
- Neck bushing is not included
- To determine bushing size, measure the outside neck diameter of a loaded cartridge, subtract .002" to .003" -- this allows approximately .001" of brass spring back for correct neck tension. Another method is to measure the neck wall thickness of a case, multiply by two, add the diameter of the bullet and subtract .001" -- RCBS suggests purchasing neck bushings one to two sizes above and below the target diameter.
- Gold Medal Match bushing dies will accept bushings made by Hornady, Redding or Wilson in addition to RCBS bushings.