I would think that if you really wanted a bit more speed from the Whelen you need a long throat and a standard Rem 700 30-06 length action. The projectiles can be seated out a bit, work the powder loads up and end up not far off the 338WM velocities. Out to 300mts IMHO you don't need the extra velocity.

The English equivalent, the 350 Rigby magnum has been used to take elephant so the Whelen should have no trouble with most animals smaller than Buffalo. As Daryl and others have said it deserves greater popularity.