I have a couple of sets one for 300wby,300win and I use them without using them to stop the stretching as I found that I was deforming the very tops of the wby cases ,you could a slight bulge at the top but they still cycled ok but I didn't like the look so I just backed off the top part and continue to use it like a regular die ,never did set the 300 win up after experience with the wby,just using it like a normal die ,like Gunnewb says there is no free lunch the metal has to go some where. Montrock