My 270 Weatherby prefers slower powders, but H1000 works well.
I only use one bullet in my 270 Bee after testing quite a few, and that’s the 150gr Partition and RETUMBO powder.
I have used 120gr Partitions in my 25-06, but I found the 115gr Partitions to out penetrate the 120’s and the accuracy was way better, along the lines of 1MoA for the 120’s & 1/4-3/8MoA with the 115’s.
I have had very good luck with 7828 in the 257. I have a tight neck reamer with the factory throat but changed to 1 1/2 degree. Shoots one whole. Start at 65 and go up from there with the 120,s. I am sure other powders work well too but this worked so good I did not explore further. mid 3300,s for speed