I first wish to point out that I find the term "Armor Piercing Gun" to be misleading. The term armor piercing generally refers to the ammunition. These rounds are shaped, and composed of materials (such as tungsten or depleted uranium) to resist distortion or "mushrooming" upon impact with their target.
It is true that the Barrett is capable of firing such projectiles. It is also true that every other firearm can do the same. An arrow shot from a bow could be "armor piercing" if tipped with such metals. Calling any weapon, including the Barrett an "Armor Piercing Gun" is like calling U-Haul trucks "Bomb Carrying Vehicles".
I wish to make known that like bombs in U-Haul trucks, there are currently federal laws in place that restrict the use of armor piercing ammunition.
The ability for a rifle to penetrate an aircraft is not unique to the .50-caliber. Aircraft are composed of lightweight materials as a result of their requirement to leave the ground. Such materials offer little resistance to bullets.
The idea that "15-year-old gang members" would be shooting at police with these weapons, as one of your audience wrote, goes to illustrate a common lack of understanding about this weapon. It is a very expensive weapon that requires years of experience to use effectively. It is heavy and requires more time to set into operation than almost any other weapon available on the civilian market. Due to it's ability to fire accurately at long ranges it does not have the ability to fire accurately at close ranges. Such a rifle has very specific application and is of little use for almost every crime.
It is true that there are fewer legal restrictions on these weapons then apply to handguns. This fact has no bearing on their availability. In my many visits to firearms vendors I have seen hundreds of handguns but only one .50 caliber BMG rifle. That store sold several handguns daily but had only sold one .50 BMG rifle in several years. The investment of thousands of dollars also deters people from purchasing this weapon of limited application.
I often hear that the average citizen has no need for a weapon such as this. I completely agree. However, the average citizen also has no need for a baseball glove or a sports car that can drive twice the posted speed limit. It is true these weapons have little value to hunters, but I know no hunter who owns one. The civilian market for these weapons lies almost entirely with long range target shooters. This is a sport, as impractical as baseball or hockey. I know of no pending legislation to ban baseball bats (an object primarily used for recreation, but could be used in a crime).
The ban is a solution to a problem that doesn't exist. Outside of military operations, I know of no aircraft, rail cars, automobiles, or people that have been fired upon with such a weapon.
I am a gun owner but not a .50 BMG owner. I do not want to own such a weapon for the same reason I do not own a baseball bat. It would not effect me if the government prevented me from owning one. What I am bothered by is the conspicuous waste by our elected representatives in pursuing legislation that does not promoted the safety and wellbeing of the people.