27 December 2018
Muley gives good advice. The neck diameter is dependent on the brass thickness and bullet diameter, you wish to use.
A .330 case neck would be for .010 brass thickness and a .309/.310 bullet. If you have the brass, size it, to get the brass thickness, using a expander, the size of your bullet, plus .001, for spring back. .332 is fine, for your chamber neck, if you want to shoot .311/.312 bullets. Or you can turn the case necks to .009.
You'll probably need something to turn necks if, you don't already have something.
The 1 degree is 1 degrees per side or 2 deg included. That is what the taper on the MX-4 30 ARD bullet is made to.
There is a bit of fine tuning, to the chamber neck and bullet fit. try things and ask questions at matches.