Re: Lee Collet die or Redding bushing die for best neck sizing?
"My runout is .001" or less measured .100" above the brass"
I use common Remington, Federal and WW brass, slightly neck turned just enough to clean up about three quarters of the circumference. I do have to cull maybe 10% of my cases but that still makes the keepers much less expensive than Lapua or Norma.
After one firing, then neck sized with my Lee Collet dies and seated with Forster "BR" dies, my runout is typically >.001", measured as close as possible to the bullet's nose. That's a much more significant measureing point than checking just out of the case's mouth. The Run-Out difference there can be as much as three times greater than near the mouth. Or more, depending on the exposed length of the bullet.
And I have used button neck sizers. No thanks, to each his own but I'll stick to Lee's.