And here is another ignorant and erroneous claim, this time from Nicole Karlis writing in Salon, about the AR-type rifle: that it is especially dangerous because the bullets that come out of it are going so fast.
Besides its efficiency, what makes an AR-15-style rifle dangerous is that it has a higher muzzle velocity, meaning that a bullet travels nearly 3,000 feet per second. . . . the velocity is a huge factor, regardless of bullet size.
This is not true.
That it is not true — and could not be true — ought to be obvious to anybody who took high-school physics. It is, in fact, as matter of physics impossible that velocity could be a huge factor “regardless of bullet size.”
Physics—how does it work?
Velocity is not the thing that matters. Bullet weight is not the thing that matters. What matters is a combination of velocity and bullet weight—which is to say, energy.
You have experienced this in your everyday life: A ping-pong ball coming at you at 3,000 feet per second is not very dangerous. A bullet coming at you at 3,000 feet per second is dangerous. A bullet coming at you at 150 feet per second is not very dangerous — you probably wouldn’t even feel it through a decent winter coat; a Buick coming at you at 150 feet per second—100 miles per hour—is.
(And if I’m remembering my high-school physics correctly, you can get hit by a cosmic ray going damned near the speed of light and not notice it at all, because it doesn’t have very much mass.)
The cartridge we’re talking about when we talk about AR-type rifles usually is the 5.56mm NATO, which does typically leave the muzzle at about 3,000 feet per second. The considerably less powerful .17 Remington moves a lot faster—about 4,000 feet per second—but is much smaller, and hence carries less total energy. I’m not going to inflict the equations on you, but the numbers are about 900 foot-pounds for the .17 Remington going 4,000 feet per second compared to about 1,400 foot-pounds for the bigger but slower 5.56mm.
Which is to say, the much slower round is about 60 percent more powerful than the faster one.
Which is also to say, Karlis’s claims about the role of “velocity” are ignorant bullsh*t, as is so much “journalism” on the subject of firearms.
The fact is—as much as the anti-gun people do not want to admit it—the 5.56mm round fired by the most common AR-type rifles is a pretty middling performer. It is, for example, less powerful than the typical round fired out of an old-fashioned .44 Magnum revolver (1,600 foot-pounds), less powerful than your granddad’s old .30-30 (2,000 foot-pounds), and just a little over one-third as powerful as a common hunting rifle cartridge such as the .458 Winchester Magnum (5,000 foot-pounds). An ordinary 12-gauge shotgun loaded with buckshot produces significantly more energy than does a typical 5.56mm round.
This is why the 5.56mm is classified as a medium-power round and always has been. The anti-gun cranks always say that they don’t want to take away anybody’s hunting rifles, but many of those are much more powerful and sometimes several times as powerful as the 5.56mm—if you have a choice between getting shot with a 5.56mm AR or getting shot with some nice Canadian’s .303 moose gun, pick the AR—you might live.
There are, of course, other factors, such as bullet design. But leave that for now.
AR-type rifles are not uncommonly dangerous. What they are is uncommonly common—the most common rifle among American shooters. Contrary to what the anti-gun people habitually claim, they are very commonly used for hunting small to medium-sized game (especially for predators such as coyote and for hogs, though I personally think it is a little small for that), for pest control on ranches and farm, and for things of that nature. The 5.56mm round is not nearly a powerful enough cartridge to ethically hunt large animals such as elk or mule deer. Until fairly recently, most states wouldn’t let people hunt whitetails with 5.56mm rifles—not because they are so powerful but because they are not powerful enough to ensure a humane kill. That purportedly terrifying weapon of war will not reliably kill Bambi. There are in fact a non-trivial number of veterans and military analysts who think it is not powerful enough for war-fighting, either — which is probably why the U.S. military is replacing it.
This isn’t some gun-nut secret. You can read non-stupid accounts of firearms physics at the Trace, for example.
Some advice to so-called journalists writing about firearms: Ask somebody who knows. Maybe read a book. Do a little—what shall we call it?—journalism.
And maybe go back and retake one of your high-school science classes—and pay attention this time.
(Correction: That 3,000 feet per second pingpong ball was out of a pingpong-ball cannon, not served with a paddle. Also, in the original version of this post, I wrote “.17 Winchester” when I meant “.17 Remington.”)