Re: How much to turn necks?
Harvey Donaldson pioneered the so called tight neck cartridge around 1945 or so, it was carried over the 222 Remington when it came out around 1950 or so. The concept entails cutting a small neck chamber and cutting the case neck to the same size as the chamber neck, thus no clearance. AKA tight neck. The case was then able to be reloaded without using a sizing die.
Using 5 different brands of cases will yield 5 different case neck thickness dimensions. Also the cases will be of different temper or hardness, so they will never be even close as to figuring the chamber neck dimension from a fired case.
Factory ammo also varies in brass thickness, as measured loaded. So, just who is to say what is standard.
.004" will work in a hunting rifle, that's what I use when I can, never had a problem with it either. The more you cut the necks down the sloppier the cartridge fits in the chamber.
Accurate rifle are interesting