.40 S&W Ammo

Jointly by Winchester and Smith & Wesson, the .40 S&W ammo is a rimless pistol cartridge. Designed to be a law enforcement round, the .40 S&W duplicates the performance of the Police’s 10mm Auto cartridge while being able to be retrofitted into small frame semi-automatic handguns. The .40 S&W round used 0.40 inch diameter bullets.

Best Caliber for Self Defense: 9mm, 40 S&W Ammo or .45 ACP?

Of all of the firearms related quarrels, none rival the argument over which auto pistol cartridge is best for personal defense. This is partly because personal protection is very important, partly because folks assume there has to be a single best answer, and finally because there exists no definitive proof that one works any better than another.

With auto-pistol cartridges a triangle analogy is appropriate because you’re trying to balance a three-sided equation. On one side of the triangle we have power, on another speed, and finally, capacity. This triangle exists because a human hand can only control so much force, because a bullet’s speed is what makes it work, and because if capacity didn’t matter we’d all be carrying derringers.

40 s&w ammo

With the 9mm Luger, .40 S&W, and .45 Auto, you have three approaches to solving the problem. Each of these cartridges has its strengths and weaknesses. So, to better understand the solution, we need to look at how each cartridge interfaces with each side of the triangle.

If we compare the commonly considered best 9mm, .40, and .45 loads using kinetic energy and momentum, we discover some interesting facts. There’s very little difference in the kinetic energy figures, but from the momentum standpoint the .45 Auto has a clear edge. But, power matters on both ends (if recoil were not an issue we’d all be carrying a .44 Magnum). Comparing the recoil of these cartridges in fully loaded Glock 19, 22, and 21 pistols, we see the other side of the power argument. The 9mm Luger generates 66 percent of a .45 Auto’s recoil, but delivers 96 percent of its kinetic energy and 69 percent of its momentum.

Some argue velocity doesn’t matter when it comes to defensive handgun cartridges. This of course is beyond absurd. The .38 Special and .357 Magnum shoot the same bullet, but due to the higher velocity of the .357, there’s no question it’s a better neutralizer. The faster a bullet is pushed, the more rotational velocity it has. This helps engineers develop more terminally effective projectiles that damage more tissue.

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