Also - take a look at local conditions and altitude for hunting areas you'd be interested in hunting.
Values can affect trajectory.

Notice you can punch in a vital zone radius and calculate a maximum point blank zero while you're at it.

Woodleigh recommends 1800-2100 fps for impact velocity.
At 300 yards that 400pp is going 1729.
You likely have room for more speed in that 458 Lott case.
2550 gets you just over 1800 at 300 yards.