The AR-15 is based on the 7.62mm AR-10 and was designed by Eugene Stoner of Fairchild Armalite. The AR-15 was developed as a lightweight model based on the AR-10 using 5.56mm bullets.

Armalite sold its AR-10 and AR-15 production rights to Colt in 1959. Colt sells AR-15 rifles to many military organizations around the world, including the U.S. Air Force, Army, and Marine Corps.

The AR-15 was gradually purchased by the US military, but it was named M16. However, Colt continues to use the AR-15 trademark on semi-automatic models of the gun offered to civilian and law enforcement buyers. The original AR-15 was a very lightweight weapon, weighing less than 6 pounds with an empty magazine. Of course, later heavy barrel versions of civilian AR-15s can weigh up to 8.5 pounds.

The AR-15 and its variants are manufactured by multiple companies and are favored by shooting sports enthusiasts and police officers around the world because they are cheap, accurate and modular in design.

AR-15 features include:

Aviation-grade aluminum receiver;

The modular design makes it possible to use a variety of accessories, and Brings the advantages of easy maintenance;

Small caliber, precision, high bullet velocity;

Synthetic stock and grip are not easy to deform and break;

The front sight can be adjusted for elevation;

The rear sight can be adjusted for wind correction and range;

A series of optical devices can be used to complement or replace mechanical sights;

Air tube type automatic mode.

There is no difference in appearance between the AR-15 semi-automatic and fully automatic variants. The fully automatic variant features a select-fire rotary switch that allows the operator to choose between three design modes: safe, semi-automatic, and, depending on the model, full automatic or three-shot burst. In semi-automatic variants, this switch can only select between safe and semi-automatic modes.