Just checked Barnes 300 WM load data.

For their 150's, they have 75 gr. IMR 4350 at 3,300 fps and 73.9 RL-17 at 3,360 as accuracy loads.

For their 155, they have 75 H100V at 3,320.

All three of those powders aren't the most temp stable.

A 150 E-Tip at 3,300+ fps should be impressive, both at the range and on game.

DF