Here is a link to a bullet sizing chart with both metric and standard measurements. Not exactly sure if this is what you are wanting but hope it at least helps.

Just remember... bullet size/bore size/caliber are all the same measurement. The "neck" of a bullet casing is where the casing is actually crimped into the bullet and I think this is the measurement you are looking for right? And then using the bullet casing as a punch?

http://en.wikipedia.org/wiki/Caliber#Metric_vs_Inch

Scroll about half way down the page and it gives you a complete sizing chart of popular calibers.