Which of these loads will go faster out of a .300 WSM?The harder alloys have more engraving pressure and will hit max pressure before a softer alloy. I think the Cayugas have a bore rider like the Cutting Edge Bullets do, CEB calls it a "Seal Tite Band", not sure if they have relief cuts in the bearing surface. I think it comes down to the Hammers having less bearing surface and being softer, more like lead, that yields higher velocities via less friction than a comparable hard alloy bullet. You will have to add more powder to get that speed though, almost like it was a lighter bullet. It is similar to the concept of the Absolute Hammer line.....less friction and more speed.
(1) Cayuga 178 with 60 RL-17, 215M, .010" off the lands, Win brass
or
(2) Absolute Hammer 178 with 60 RL-17, 215M, .010" off the lands, Win brass