RE: 378 Velocity
http://www.barnesbullets.com/files/2018/03/378-WBY-Mag.pdf Not as much as I thought it would be but pretty respectable at over 3,000.
The various 250s have performed well for me but especially for Africa I would think the 270s could be better. I might be tempted to use the TSX instead of the LRX on buffalo but I haven't tested either so no basis for that. The LRX would shoot similar to the 30-06 165s and would give some long range advantage.