The heaviest .45 ACP bullet weighs 230 grains, and travels at about 850 feet per second. This gives it a muzzle energy of about 502 Joules.
The heaviest .40 S&W bullet weighs 180 grains, and travels at about 1000 feet per second. This gives it a muzzle energy of 544 Joules.
So, in theory, the .40 S&W can be more powerful.
However, there continues to be debate over which round is the best at putting someone down in a fight. This is because there are factors which determine a bullet's effectiveness other than muzzle energy.
Without getting into all of *those* details, I think that everyone can agree that both the .45 ACP and .40 S&W are effective calibers for self defense, particularly with well-designed hollowpoint ammunition. And with all other things being equal, these two rounds are far better than the .380 ACP, 9mm Parabellum, .32 ACP, or .22 LR.
By the way, I'm a .45 ACP fan, all the way.
· 1 decade ago