Ok, sierra reccommends one bullet width of bearing surface in case neck (.308). But when i measure how much bearing surface is in neck of factory 168, or 175 fed. Gold metal match I get .260 bearing surface in neck. So how could they recommend this if they dont do it themselves?? I ask because my rifles coal is 2.931 with the 175 smk. I was gonna start my loads halfway between 2.800 and 2.931, which makes 2.865. That leaves .200 bearing surface in neck, is that enough in your opinion?