Like many, I started with Lee dies and equipment. And like many, had no use for Lee's die lock rings. You know the ones that relied on an O-ring to keep everything in place. They worked half a$$, if you tightened with the lock ring, not touching the die body. A finicky pain . To the millwright in me , a setscrew into threads was just plain wrong, like RCBS and Redding do. I guess once you've set your die and buggered up your threads, you don't have to change your setting. I guess that was their thinking. When I saw Hornady clamp type lock ring, I was sold. Industry uses clamp type lock rings on machinery sometimes. I was gradually changing over my dies, but it's another expense. Lee has come out with a cheaper clamp type lock ring. They have kept the O-ring as well. The O-ring gives some self alignment to the dies. Threads by their nature have some slop.