It's funny you say that, because, if anything, their lock ring bugs me a little, so I use Hornady split rings, instead of the O ring nuts. To center the die, I put a case into the holder, run the ram up, into the die, then run the nut into position, and lock it, with upward pressure on the die body. That centers it in the threads, and locks the die into that position. I've done that for so many years, and never had issues. Another thing I do, is put a dot, on the lock ring, and on the press, and always index them together, with my wrench, when I change out dies. Maybe it's a OCD thing, but it works for me, and I feel assured it's where it's supposed to be, everytime! Just my experiences, and opinions!