My experience with the hydro die I had was that it was a waist of money. I didn't like the fact that I had to hit it with hammer (rather hard) while it was in my press (the thing I expected to load precision ammo with). That and the fact that I had to fire from the cases anyways to get the shoulder right, killed the whole concept to me. Had to do this even when oversizing a bit (as stated by another) and setting the shoulders back. And it was messy and added way too much work.
Neat idea, but a dud to me.
Neat idea, but a dud to me.