I believe the charge was 68.0gr. BLC2 with a CCI250 primer with the 270gr. Speer, which turned out to be a VERY soft bullet when driven at a low 2,300 fps from my 9.3x57.
My load with the 286gr. was 65.0 BLC2.
I worked up to those from well below and they were quite safe in my rifle.
I see now that Hodgdon only goes to 66.0gr. with the 270 Speer bullet. From what happened to the 270 Speer from my light load in the 9.3x57, I would expect that bullet to fragment badly if it strikes with more than 2,000fps. Vel.

In my .375/06IMP, a charge of 66.0gr. BLC2 delivered a 270 Barnes TSX at excessive speed and I reduced its charge, perhaps not enough and they are still smoking hot at 2,650fps.
It is possible the BLC2 of 2010 is hotter than the BLC2 of 1984.

Both of these rounds have the same capacity of 78.0gr. With identical loads using the same bullet characteristics should produce similar pressures, with the larger bore developing less pressure.
Since I was using the TSX in the .375, that will have increased its pressure somewhat. I was shocked to find 2gr. Less powder(66) in the .375 produced and additional 70fps over the 9.3x62. That scared me so I reduced the load to 63.0 gr. For an even 2,650fps.