The official designation of rifles designed by the Armalite Firearms corporation. Although several AR designated rifles do not fit the description, the AR-15 has become so ubiquitous in the firearms community that “AR pattern” or “AR style” has become the term used to describe any of the variants based upon the basic concept of the AR-10 designed for Armalite in the 1950’s.
This style of rifle is characterized by modular construction based upon a two piece receiver system including the upper receiver – containing primarily the barrel, gas system and bolt carrier group, and the lower receiver – containing primarily the fire control group and buttstock.
The modular construction has made AR pattern rifles the most popular rifle type in the US due to easy adaptability to each shooter’s physical needs and personal preferences.
Although commonly (and intentionally) equated with “weapons of war”, the only relationship with military firearms are cosmetic. Civilian AR style rifles are semi-automatic rifles that are functionally identical to any number of “traditional” semi-automatic hunting and sporting firearms.