RE: 257 Roberts +P Brass
I have been loading the 257 Roberts since 1976. I loaded at first for a friend who liked the 117 grain Hornaday bullets. I don't have his loads in my book anymore. I load for my own as well but I think the Roberts is most effective with 100 grain bullets. My load is from one of the old Hornady Manuals. If you try this load, start a grain or two lower at first. I am shooting a 700 Remington with a 22 inch barrel. I am loading 46.0 grains of H414 in the +P Winchester brass with a WWMagnum Primer.and the 100 grain Hornady interlock. They Chronograph at an average of 3084 fps. My OCL is 2.774.