Beginning with Vietnam, American soldiers and Marines have carried the M-16 rifle. And the virtues and vices of the black rifle have been argued by military men and gun enthusiasts ever since. The central issue in the argument is the .223 caliber, or 5.66-millimeter bullet, fired by the M-16. "Before Vietnam," explains Jason Kuyper, manager of Southern California Guns in La Mesa, "the military used a heavier-caliber weapon. It was a .30 caliber, and now it's basically a .22 caliber. There's a significant difference in both the size of the bullet and the energy it delivers."
The size of the bullet fired by a gun is denoted either in caliber rating or in millimeters. A .22 caliber round is 22 hundredths of an inch in diameter. A gun firing that size bullet will commonly be called a "22." A 9-millimeter handgun fires a bullet 9 millimeters in diameter. In the interest of uniformity, militaries in NATO countries officially use the metric rating. But in the United States, gun owners usually speak in terms of caliber. Hence, in the case of the M-16 service rifle, its round is known both by its caliber, .223, and its metric size, 5.56 millimeters.
"Guys that are from the younger [military] generation," Kuyper says, "and raised on the newer generation weapons, they don't have a problem with the M-16 and the .223 round. But you have the guys who are a little bit older, and they were around when the heavier-caliber weapons were issued, guys who were in the military in the early '60s and WWII vets and Korean War vets. Those old-school guys think that the new stuff is junk, and they call it a 'mouse gun.' "
Kuyper chuckles, "Well, in general, .22 caliber weapons are used for varmint hunting -- prairie dogs and gophers and that kind of stuff."
What about hunting something the size of a human?
"It depends," Kuyper answers. "There is kind of a dividing line right at that size game. Game similar in size to a human would be deer and people have different opinions on what you can hunt deer with. Some people use a .22 caliber to hunt deer, though people generally will use a .30 caliber because of the stopping power of the larger round. They know that the .30 caliber will kill the deer in one shot, and they don't want to see the animal suffer. You don't want to wound game and let it run off and lose it. And in dangerous game, you don't want to shoot it and have it turn around and attack you."
Former Navy SEAL Bill Salisbury fought in Vietnam with the M-16 and a shortened, or carbine, version thereof known then as the Car-15, now as the M-4. A freelance journalist with close ties to the SEAL community, Salisbury thinks a soldier who had grown up hunting human-sized game with .30 caliber bullets and varmints with .22s would feel uneasy, carrying a .223 caliber weapon into combat. "It would look like a toy to him," Salisbury says, "until he saw what could happen with that .223 round. First of all, it is not a .22, it is a .223. And it has got a little more powder in the jacket, too, so it's coming out with more velocity than what you shoot squirrels with. And, because of the way it was designed, it has a stopping quality of its own."
Salisbury explains, "The scientists who developed the [.223] round designed the bullet to be unstable, which meant it was not unstable in flight, but when it struck something it immediately became unstable. So instead of blowing a big hole through somebody, like in the Dick Tracy comics, it started to tumble and tear."
"In World War II and Korea," Kuyper says, "the theory was using one large-caliber bullet to kill one person. In Vietnam, the combat theory shifted to thinking you are more effective if you don't kill the guy. You are more effective if you wound him because then it takes three other guys to carry him off the battlefield and you now have taken out four soldiers instead of one. The high-velocity small projectile [.223] round is less lethal, but it causes a very messy wound because it bounces around inside of you and makes a big mess."
That theory, Salisbury says, was at least partially proved in Vietnam. "I saw a person who was hit in the buttocks with a .223. It was the only round in her yet she was dead within 30 minutes. We tried our best to save her, but what happened was that round, when it entered her buttocks, began to tear and tumble and it went up through her intestines and her stomach and God knows where else, and that is what killed her."
Yet the theory proved to have flaws as well. "The trade-off for the stopping power," Salisbury explains, "was going to be this tumbling effect. But that tumbling effect was also a drawback because anything that round hit on its way to the target would cause it to go unstable and go off course. With the M-14, which was the service rifle we had before the M-16, the 7.62 [millimeter] round, that round would go through a small tree branch and continue on its way. But the instability that was built into the 5.56 so that you'd get this horrendous effect when it hit the target, that same instability would cause it to fly off course if it hit something like foliage or small tree limbs between you and the target."
Kuyper points out that the maiming effect of the .223 round fired from the M-16 is only half of the combat theory. The other half has to do with weight. "One individual soldier can carry almost 400 rounds of the .223 into combat," he explains. "Previously, soldiers were issued 200 rounds of the .30 caliber and it was extremely heavy. You couldn't load up with that stuff because it was a bigger, heavier bullet and you couldn't carry all that weight."