The Yaniro slot crimps have no substitute when it comes to forcing a positive semi-closed crimp. This grip type is such a weakness for so many of us. It has to be trained carefully, and it can easily be "faked" by rounding over on crimps. These grips force the hand to be semi-closed. They are so good. The clay-like texture is amazing for long sessions. If you are dry fire off of them, my guess is that there is a correction to make in the feet or body position.