Forster neck sizing bushing are made to use with the Forster Precision Plus Bushing Bump Dies only, and they are not interchangeable with other brands of bushings. Forster bushings are made in .001 inch increments in the sizes needed for the dies Forster makes. All Forster bushings are cryogenically treated to make them ultra smooth and long lasting.
Sinclair, Issue:1B, Page:052