There are millions of ARs in America... 

Via WBIR:

Law making should be based on facts. We estimate 13.7 million semiautomatic rifles of the type wrongly termed “assault weapons” are in the hands of Americans. They have been in the public market since 1964 and are the nation’s most popular rifle, used for a variety of legitimate purposes, including hunting, target shooting and personal defense. They should not be banned.

More accurately termed “modern sporting rifles,” they fire one round with each pull of the trigger and come in several calibers. They are no more powerful than other rifles. What differentiates them is cosmetic, such as the type of stock that makes the conventionally operating rifle look more like a military firearm.

These rifles are not machine guns or automatic firearms, which were severely restricted from civilian ownership under the 1934 National Firearms Act. The “assault weapon” term was conjured up by anti-gun activists to deceive the public into thinking they were machine guns.

Read more here.