I would also go wiih IMR4350, but have pointed out many times before now that maximum charges in the 7x57 depend a LOT on throat length, which can vary considerably. As a result maximum loads can vary 2-3 grains, depending both on the throat and bullet.

With 160's I tend to load to 2650-2700 fps, depending on barrel length rather than exact powder charge.

“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck