Well, they are all essentially the same - in that they mushroom out to create a bigger wound channel, at the expense of less penetration. However, some open up very fast, some have a delay, some just don't open up all that much. And then how much resistance the bullet encounters makes a lot of difference. The shoulder of an elk can cause a bullet to explode that is normally a pretty good controlled expansion bullet going through the chest of a deer.

And, last, the impact velocity can make a big difference. A certain bullet can be a deep penetrating bullet at 2100 fps impact velocity, and rapidly expanding bullet at 2800 fps, and an exploding varmint bullet at 3400 fps.

A lot of shooters bounce back and forth throughout their hunting days going from faster expanding bullets, that kill well on broadside rib shots but ruin a lot of meat and come apart on big bone - to deep penetration bullets that break big bones well and don't ruin much meat, but don't kill very quickly on broadside rib shots.

Some of these new bonded bullets; like the Scirocco, Accubond, Trophy Bonded, Fusion, etc; come as close to doing it all as anything that has been made in the past.