To quote Frank from Bartlein on another forum:
Q: Frank, is there a typo on your contour chart or is the neck diameter of your #0 contour really bigger than your #1, #2, #2B, and #3 contours?
A: No not a typo. The #0 contour is kinda like a Win. Fwt contour but doesn't have the double taper of the Win. Fwt. contour. So the neck area is bigger. From the radius it just straight tapers down. Again though not recommended for magnum calibers.
