When you ask "What die for best accuracy?", are you using a benchrest rifle/chamber, or a factory rifle with a field chamber?
There is a world of difference.
When a bench shooter FL sizes his case, it is just a tweak, because the die and chamber are just about the same size, so there is little change in the case - the shoulder is set back 1 or 2 thou just enough to make sure that there is no resistance in closing the bolt.
But when a case that is fired in a factory (or custom rifle
with a field chamber) is sized, the case is reduced in size quite a lot.
The shoulder can be set back as much as 14 thou (or more), and the body can be reduced 6 to 8 thou. That's a LOT of rattle!!
In "non-benchrest" chambers, neck sizing is better for case life, and more accurate.
This is an "Apples and Oranges" thing.
If you are not shooting a bench gun, don't assume that bench techniques are best for you.