Semiautomatic assault weapons like Sig Sauer’s MCX are civilian versions of military assault weapons. Even though the gun industry prefers to call semiautomatic assault weapons “modern sporting rifles,” there are no significant differences between them and military assault weapons.
Military assault weapons are selective-fire. That is, they are capable of fully automatic fire—or three-shot bursts—as well as semiautomatic fire.
Civilian assault weapons are not machine guns. They are semiautomatic weapons. (Since 1986 federal law has banned the sale to civilians of new machine guns.) The trigger of a semiautomatic weapon must be pulled separately for each round fired. A machine gun will continue to fire as long as the trigger is held down until the ammunition magazine is empty. It is a mistake to call civilian assault weapons “automatic weapons” or “machine guns.”
This is a distinction without a difference in terms of killing power. Civilian semiautomatic assault weapons incorporate all of the functional design features that make assault weapons so deadly. They are arguably more deadly than military versions, because most experts agree that semiautomatic fire is more accurate than automatic fire. As the U.S. Army’s Rifle and Carbine Training Circular notes, “Automatic or burst fires drastically decrease the probability of hit due to the rapid succession of recoil impulses and the inability of the Soldier to maintain proper sight alignment and sight picture on the target.”
The distinctive “look” of assault weapons is not cosmetic. It is the visual result of specific functional design decisions. Military assault weapons were designed and developed for a specific military purpose—laying down a high volume of fire over a wide killing zone.
Civilian assault weapons keep the specific functional design features that make this antipersonnel function easy. These functional features also distinguish assault weapons from traditional sporting guns.
The most significant assault weapon functional design features are: (1) ability to accept a detachable high-capacity ammunition magazine, (2) a rear pistol or thumb-hole grip, and, (3) a forward grip or barrel shroud. Taken together, these are the design features that make possible the deadly and indiscriminate “spray-firing” for which assault weapons are designed. None of them are features of true hunting or sporting guns.
Although the gun lobby today argues that there is no such thing as civilian assault weapons, the industry, the National Rifle Association, and gun magazines enthusiastically described these civilian versions as “assault rifles,” “assault pistols,” and “military assault” weapons to boost civilian sales throughout the 1980s. The industry and its allies only began to use the semantic argument that a “true” assault weapon is a machine gun after civilian assault weapons turned up in large numbers in the hands of drug traffickers, criminal gangs, mass murderers, and other dangerous criminals.