Asking a threat (be it animal or man) to please hold while you swap mags is just asking for a trip to the local cemetery.
I think this is relevant:
I wanted to use a certain caliber rifle for a dangerous game hunt. Researching it, I found that an expanding bullet was the best, safest choice for a broad-side first shot...but that all other angles would require a solid bullet.
Can you imagine lining up a broad-side shot, then the animal turns--you eject the expanding round in the chamber to get to the solid in the magazine--and then the animal turns back broad-side again. All the while, the animal's thinking, "What's making that bolt-action rifle-sound over there?"
So commenced a search for the perfect bullet (sound familar?) that would work for
all presentations of the animal. And I actually found it! And then found it wouldn't shoot accurately out of my gun.
Then, belatedly, a brainstorm: "Hey, what if I go up in caliber?" "Oh, that would make it easy: then you just use
this bullet for all possible first shots."
:banghead:
Larger caliber is sometimes the answer.