I have read the previous threads about FL vs NS, and I have a question. I want to see if I got this right. If you have a factory action, with a factory barrel then you should lean toward NS because of the looser tolerences. But if you have a custom/blueprinted action, and a custom barrel then go with the FL becasue of the tighter tolerneces. This is just to make sure the case/bullet will chamber, and for better accuracy.
I just want to add this as well. I know that every rifle, case, bullet, powder reacts different, my question is more or less speaking in general terms. I am not looking for a short cut, or asking someone to look into a crystal ball. I just wanted to make sure I have the "Theory" right.
I am no expert but I would say that it is the other way around.
With a factory chamber that will not be as well reamed as a custom one, you need to FL size or at least PFLR and size the case body in order to keep an out-of-round factory chamber from influencing the orientation of the neck and bullet to the bore. With a custom chamber that is much much more likely to be closer to perfect than a factory one, the fire formed case body will be very close to perfectly round and if you don't size the case body it will be less likely to bind in the custom chamber due to orientation.
I have seem benchrest shooters who load at the range and they wil not size the case at all. The neck is tight and they don't use stiff loads. They just prime, charge and seat another bullet.
If you can read this, thank a teacher.......if you are reading this in English, thank a soldier.
"I know that every rifle, case, bullet, powder reacts different, my question is more or less speaking in general terms."
Such theories are (more or less) of no help; only facts are helpful and none of us can provide you any valid facts. You already recognise there are no valid rules so trying to give an indefinate application to factory or customs is meaningless, they are each individuals and must be treated as such.
If/when I want to know if my rifle/load shoots better neck or FL sized I try both, then I have usable facts. Even when there is a difference, it's never vast.
Some benchrest shooters FL size all the time. I neck size until bolt lift gets difficult, then FL and bump the shoulder slightly.
But I never neck size for a hunting gun. I want my reload to feed and exract as smoothly as possible, and this does not always happen. And, full length sizing works the brass more, leads to shorter case life.
As far as factory cut chambers vs. custom cut chambers, I really believe it is a crap shoot. I will neck size only if I have a chamber that is cut long so that F/L sized brass stretches excessively with each firing. The worst chamber for stretching brass I have had was a custom barreled 264Win mag with a Shilen match grade barrel on a FN Mauser action. I think the belted magnum calibers have the most potential for a chamber that is of generous proportions because they headspace on the belt rather than on the datem line of the shoulder radius. I don't neck size unless I believe I have a valid reason to do so, and don't want any rifle that won't easily chamber ammunition. Now you have my 2cents worth on this topic. As they say opinions are like A holes, as everybody has one.