I did some checking last night just to satisfy my curiosity. To me neck tension has to "feel" right, and on the cartridges where it feels right to me they are running .002 to .003 neck tension. These are mostly mid-capacity cases with plenty of bullet in the case mouth, and annealed every other firing. .004 is getting too tight, really having to cram them in there. And .001, while it might be great for single loaded target ammo, just doesn't have enough grip for field use IMO.
Some cartridges I use bushing dies and swap bushings to get the feel right. I do have some Lee Collet dies as well. It seems to me the Lee's come up pretty light on neck tension for my taste, in general. Most of the collet dies I use I have ended up chucking the mandrel in the lathe and polishing it down just a bit to get an extra .001 or .002 neck tension.
