At 1300 fps you do reach as deep a penetration-level as the higher velocities do and with less recoil. You may go up in velocity but the returns for a hard-cast bullet in terms of increased penetration is not appreciable really. I agree with that sweet-spot designation. The 480 Ruger is an example. It has adequate power and penetration with appropriate bullets for anything that walks, crawls or approaches with menace and mayhem in mind, but is running bullets 100 fps or more LESS than the same in a 475 Linebaugh. So I would really concentrate on good bullet choices as well as hitting the vitals, because that is a never-changing requirement.