Barnes doesn’t list that bullet for the 6.5-300. It should do around 3500 FPS plus.
Maybe they haven’t gotten around to it.
26 Nosler is pretty close. 120 TTSX is my bullet of choice, accuracy at 3,450.
I think you could use 869 powder, start with 26 Nosler data, work up from there. 3,500 not a problem.
DF