Re: I need some help explaining this one
"School #1 With a factory chamber you should not neck turn because it just causes the bullet to be low in the throat.
School #2 With a factory chamber it is good to neck turn to get uniform neck tension on the bullet.
It seemed to me everybody was pretty consistent that with a custom chamber neck turning was good."
I think this #1 is accurate information. A very minor clean up, after FL sizing, helps on case neck uniformity. Don't expect miracles. But, if you don't know the chamber dimensions, you can't know where you need to stop on the neck turning. 25%/50% removed, for example.
For number #2, I can't agree with that. That applies for a tight neck in a custom barrel. In which case, you will probably know your neck O.D. and a good idea of your wall thickness, and can order those "fancy" bushings in the correct size. And, you may not get it right, the first time? This is stuff that does not apply for a factory barrel....usually.
In the case of a 220 Swift, for instance, you may see thickened and excessively long necks. Then, you need to trim to length, and decide whether to inside ream or outside turn, avoiding the dreaded "donut".
Good hunting. LB