I always thought a "long throated" .264 Mag.,  set up to seat 140 grain spitzers with the bullet base flush with the case neck and loaded to full length overall magnum (i.e. 300H&H) length with a 25" barrel would be kind of cool.   YOu should be able to hit 3,200 fps with the long, sleek 140 grain spitzer.    Kind of a speciality item, but very cool.