It's funny in a way -- obviously FMJs can kill, and kill perfectly well. "Dead right there" as they say.
We all spend a lot of time and energy trying to pick what's the very most perfect balance of performance between this and that bullet, at this or that speed, and the manufacturers spend millions to develop something just a little better, just a little more consistent, that holds together under just a little bit harsher impact, etc. But it is incredibly hard to
quantify how much difference any of that makes on game.
We all know it makes
some difference, of course, and have seen examples of really great tissue damage, wound channel, and so forth with various bullets. But the fact remains that we DIDN'T see exactly the same shot made with an equivalent FMJ round at the same time. We didn't see that animal stagger off wounded because of a "good" FMJ hit, and the same animal die from the same HP or SP hit. All of our beliefs about the matter are a combination of (usually just a little) personal observation (just a little, as very few of us will ever take a shot at an animal with an FMJ at all!) and a whole lot of advertising, and what we hear other people say (who often have just a little personal experience as well). And we are subject to having heard many tales of this or that bullet "not performing" which we may believe would be more truthfully told as the HUNTER not performing his job correctly than in implicating the bullet -- whatever it was.
Of course, we know that a perfect hit with an FMJ will kill just about anything on earth. So what we're trying to buy with higher performance ammo is margin of error for our imperfect shots. And we believe we do buy some with our hollowpoints and other expanding ammo, but is that margin of error 2%? 20%? 90%? There's no way to
really tell, so it becomes a matter of "faith." And like religion, mine's better than yours!
Many different kinds of rounds (from patched round balls to saboted shotgun slugs to "Bonded Core Ballistic Tip Terminal Triple Whammy" bullets -- from everything between .17 cal up to 12 ga.) will kill an animal as quickly as we might like under the right circumstances. Or WON'T, under the wrong ones.
What is "ethical" as regards killing a living being is a hotly debated topic here. (Call it "predators' guilt," I guess.
) But everyone seems to have different boundaries for "ethicality." An animal killed "DRT" with an FMJ is no less ethically killed than one that gets eviscerated by the most impressive expanding HP anywhere. An animal head-shot with a .22 LR that falls to the ground and expires is ethically killed -- or as ethically as killing can be accomplished.
But is it ethical to TRY to make that perfect shot, believing that your margin of error is small?
If you are trusting your life to the meat you bring home, and your bullet of choice is an FMJ -- and you're killing what you shoot at with reasonable certainty -- no one on earth can tell you you're acting unethically.
If you (as I do) wish to increase that ephemeral, impossible to quantify, "safety factor" by shooting an expanding bullet, that's certainly no less ethical. Maybe there's even some real benefit to it. The manufacturers of bullets, and many of the state game departments, sure would tell us we may believe it!