I’ve kind of wondered the same thing (though I haven’t played with either 4895 in any of my H&Hs). I recently shot a few 270 RN Hornadys over screens and saw 2400+ with 58.0 grains H4895, 2500+ with 59.0, and close to 2600 with 60.0; these speeds in a 20” 350 Rem Mag case/chamber necked to 375. TAC gets even more interesting.
2600 fps with H4895 and the 260 Partition in a short action 375 seems adequately lethal for my purposes.