RE: Who makes the Best Quality Dies?
I have used several brands, Lee, Lyman, C-H, Pacific, RCBS, all do well enough, the Lee dies have the best instructions.
I have modified all my lock rings to use O- rings and thrown away all the locking set screws, have never had a Lee locknut change adlustment.
They do not screw up the threads on the dies , either.
Don[8D]