I turn all my necks, and changing out my dies to bushing dies. I hadn't paid much attention to it. I started turning necks in early 2000. I am not for sure if they there was bushing dies at that time. I lighten up my neck tension on my reloading without even knowing what I had really done. I changed the tension, and for the better. Now you have other ways to do that. That would reduced the tension. I did set the thickness and didn't change it in cutting my necks. You will need to check the neck thickness to see how much they are out. So to me setting the thickness is a must. I my newest rifle, I am reducing the neck dia, and will have to cut my neck to fit.