Thread: Full Length or Neck sizing. What is better and why?

Originally Posted by zimmer

The worst die to induce runout is the Redding body die. The neck being unsupported is free to move where it likes.

I have resisted buying a runout gauge and tried to keep my head firmly buried in the sand to pretend that runout doesn't exist (and so long as I continue getting good groups and low SD/ES it'll probably stay buried too). But it would be interesting to see what kind of runout I'm getting on the finished product with the body die and collet die combo (Forster FLS dies are my 1st pick too but for 22-250AI that wasn't an option). Results so far suggest if there's any runout, it's not doing any harm.

Hazarding a guess, the more the body die has to squeeze the case and bump the shoulder, the more potential there is there for the neck to wander. How square the action is and the uniformity of the brass must really start to matter too.