wombat,
I will answer your queation in two parts.
First the Ballistics:
I shot 2 buffalo and 3 elephant. I used one 480 Woodleigh Soft on one buff and 2 500gr Swift A frames on the other. All Softs were recovered perfectly expanded. I also shot some 480 solids into the buff as finishers.
2 cow elephants were brained, one frontal, one side. Both Solids exited the brain pan in the skull but did not exit the elephant. The frontal recovered in the spine, bullet split open on the spine. The side was at an angle, broke the atlas and axis when it exited the brain pan, and was just under the skin in the neck behind the ear.
On the bull the first 2 solids were fired at a walking elephant. The first shot hit low in the left shoulder entering low in the chest. That shot stopped his foward motion. He began to spin to his right, the second shot broke his left front leg, below the shoulder, exited and went through the trunk.
He spun around and came for us. He covered 3 or 4 body lengths, stumbles and fell down. I ran toward him and when he got up the PH said "Brain Him" so from about 60 to 70 yards I brained him with a slight quarting head shot which knocked him down. I then ran up and put 2 more shots in his head. All Solids were 480 Woodleigh's. Velocity of the 480/500 gr bullets is @ 2100 to 2150 fps [I have not chronoed my RL 15 loads yet]
I was extreamly happy with the power and performance of the 450 No2.

Now to the second part of my answer, the experience of hunting Africa with an Original British Double Elephant Gun:

PRICELESS.

Nothing can compare to hunting elephants and buffalo with a double rifle. I would not want to do it any other way.