Haven't had a chance to work with a 480 but own both a 460 and a 500.
Both can be loaded from mild to insane and both will do a lot of damage; usually to much.
What the 460 is designed for is 100+ yard shots were its extreme speed will help it out, giving it a flatter, and more predictable trajectory. Shooting it at sub 50 yards is really a waste since it will more than likely cause extreme damage to the game. The gun is designed for long range shooting. As said below, a 45LC will kill something just as dead as a 460, just can't do it at the same distances. At the same time though, you can load some pretty heavy bullets up and tone the velocities down a bit. Ranger Rick makes a 535gr WFNGC bullet that would be great for more modest velocities and excellent penetration.
The 500 on the other hand is great for lobbing huge bullets at modest velocities for taking down T-Rex and other exotic game. Ranger Rick designs a 700 gr cast bullet that can be launched at close to 1400 FPS. I've also seem some custom molds that produce 820gr cast bullets. Don't know how fast you can shoot them, or if you could stabilize them in an 8 3/8" barrel, but I know some people are trying. The amount of penetration would be pretty insane.