I'll take the liberty of reordering some points made by Frank ettin in Post #40:
- Holes in the right places are better than holes in the wrong places.
- Holes that are deep enough are better than holes that aren't.
- More holes are better than fewer holes.
- Larger holes are better than smaller holes.
The first and second are obviously of equal importance. The third is true in its own right, but in practice, it also helps to achieve the first. The fourth is last for a reason.
I'll add a fifth point: too much penetration is of little use and can become a lability.
From the standpoint of terminal ballistics only, if a bullet accomplishes the second, it doesn't matter one whit whether it is heavy and slow or lighter and faster.
Penetration is a function of mass, velocity (squared, actually), and bullet design, the third item taking into account sectional density, shape, and what happens to the bullet upon impact and during its journey in the target.
If the bullet penetrates enough, it does not matter why. And anything that passes the FBI tests will do the job.
But terminal ballistics is only one aspect. In order to address the first and third items in a violent encounter with a moving target, one must be able to shoot
very fast, and
with sufficient accuracy,and that requires that recoil not be excessive, and one must have sufficient magazine capacity.
The 9MM parabellum rounds of 1908 would not meet the requirement to down a horse, nor would we be apt to choose them today. But things have advanced a lot since then. The larger capacity and lighter recoil of todays's 9MM loads are two of the reasons that the pendulum has been swinging from the .45 ACP and past the .40 S&W to the 9.
Rob Pincus has made that journey and says that he has to admit that he was wrong in the old days.
I knew none of the above when I chose a .45 five years ago.
