Ok, as you said you wanted the best die. There would be no better die then the Warner Tool Company (WTC) dies it will
At some point, you have or you will spend the money for a high dollar target rifle. Why feed it ammo from a commercial, off-the-shelf die that may or may not yield optimum results for concentricity and brass life. WTC Dies are made from samples of your fired brass to full length size only .001 to .0015" on the body diameter and just enough on the necks to get 30, 40, or even 50 reloads from your brass (neck annealing required).
Concepts - This is what WTC Dies will give you:
Minimal brass sizing for flawless chambering and maximum case life.
Concentricities of .0005" or better from top to bottom.
Head space adjustment within the die via hardened and ground tool steel retainer rings.
Standard die body will accept die inserts for any caliber from 6mm to 30-06.
Now introducing the Magnum die body that will accept larger cartridges up to 416 Rigby.
2 part die insert construction - one for the body, one for the neck and shoulder.
I am only aware of a few people that use this die and swear by its performance.
I would like but do not have this die i use a Lee collet die for final neck sizing and a Redding Full Length sizing die with bushing for body and initial neck sizing.
Trevor