Yes, we do math here. Emily is taking you back to old-fashioned book learning. With a very practical application.
We’ve recently shown that, yes, you can accurately shoot a .22 Long Rifle bullet and hit a 5” target 300 yards away. It does take practice, but so do all good-to-have skills.
So what? Well, can that round be lethal at that range? It might be nice to know if there was a tasty rabbit or a less tasty squirrel or other source of protein out there. And you just couldn’t get any closer. Or if a farmer asked you to clean out ground hogs, woodchucks, whatever from his plowed fields. But does the .22 have the kinetic energy sufficient do to so?
Now, math. Kinetic Energy is one of several ways to measure bullet effectiveness. Let’s make some comparisons using our KE = 1/2 x Mass x Velocity Squared. For a .50 BMG (like from a Ma Deuce machine gun), plug in bullet weight of, yes, 660 grains and a muzzle velocity of 2900 feet per second. Kinetic energy comes out to an amazing 12,324 foot pounds. That’s lethal to light armored vehicles at a mile.
How about an M4/AR15 round? Plug in 62 grains and 3,025 fps and you get 1,260 foot pounds, generally accepted as lethal to humans at 500 yards.
How about a 1911 shooting a 230 grain bullet at 850 fps? 369 foot pounds. Clearly lethal at pistol engagement range.
But how about a tiny little 40 grain .22 round traveling at 1,260 fps? A paltry 141 foot pounds. And that’s at the muzzle.
“But, Mr. Red”, you say, “.22s have killed a bunch of people!” Yep. It’s called ubiquity. It’s not magic; there are just a metric sh*t ton of .22s.
The .22 is not generally accepted as a self-defense round, but shear numbers give that result. So there’s something more going on than just energy.
Tomorrow let’s talk about bullet design, wound channels, cross-sections and bullet placement. But still keep in mind our long range .22 shots.
KatNap Fever! 