Lets not forget the Rigby 275 HV load. This was a 140gn Spitzer bullet driven at 2,800 fps. Many manufacturers load a 140gn at about 2650, but with a decent strong action you can easily shoot a high BC 140 or even 150 gn bullet to shoot at the 2800fps plus sorts of velocity. This gives plenty of downrange energy. With a modern rangefinder and knowing the trajectory ability to make first round hits at much greater than point blank becomes much easier. And it will pretty much mimic the 270win.