Interesting concept. But I think there is a lot to be said for using one medium to heavy bullet in a caliber and becoming completely familiar with its trajectory. The 375 h&h is a great example, pick a good bullet from 260 to 300 grains and go to work. Is there really that much to be gained by playing with a lighter, poorer sectional density bullet even at longer range? I don't think so, especially now with good rangefinders so available. That bigger bullet will get the job done at any sensible range and the shooter will be spared trying to remember trajectories for different bullets and fiddling with his sights every time he makes a bullet change.