My dad shot competitively in the 60's, 70's and 80's and loaded the 158 grain HBWC (hollow base wad cutter) using 2.7 grains of bullseye. I now have his Star reloader and it is set only for 2.7 grains. As I also recall, Star Reloading in Indianapolis also loaded their match ammo this exact way. I believe that the 2.7 grains of bullseye behind the 158 grain HBWC to be the standard for Bullseye shooting.