Dammit Jim's Gun Info brief overview of the AR-15 weapons platform.
Disclaimer: AR-15 in 5.56 is NOT big-bore :)
The AR-15 is a civilian, non-select fire version of the M-16 rifle.
The AR-15 is an air-cooled, gas-operated, magazine-fed rifle manufactured in the United States between 1959 to the present, and originally adopted by the United States Armed Forces as the select-fire M16 rifle. (rifle had safe, semiautomatic, and fully automatic fire rates) Designed by American gun manufacturer ArmaLite in 1956, it was based on its AR-10 rifle. The ArmaLite AR-15 was designed to be a lightweight rifle and to fire a new high-velocity, lightweight, small-caliber cartridge to allow infantrymen to carry more ammunition.
In 1959, ArmaLite sold its rights to the AR-15 to Colt due to financial difficulties and limitations in terms of manpower and production capacity. After modifications (most notably, the charging handle was re-located from under the carrying handle like AR-10 to the rear of the receiver), Colt rebranded it the Colt 601, however, it still carried the Armalite markings due to contractual obligations to Armalite/Fairchild Aircraft Co. Colt marketed the redesigned rifle to various military services around the world and it was subsequently adopted by the U.S. military as the M16 rifle, which went into production in March 1964.
Colt continued to use the AR-15 trademark for its line of semi-automatic-only rifles marketed to civilian and law-enforcement customers, known as Colt AR-15. The Armalite AR-15 is the parent of a variety of Colt AR-15 and M16 rifle variants.
Due to law changes within the United States, semiautomatic versions were made available for civilian usage and its popularity exploded on the civilian market.
Because of the Vietnam war and the subsequent cold war with the Soviet Union, the AR-15 rifle became the symbol of freedom against the AK-47 style rifle which represented communism.
While AK-47 style rifles and their derivatives are popular in the United States in their semiautomatic configuration, the AR-15 remains the more ergonomic between the two.
There are a lot of accessories for the AR-15 rifle (it's AR meaning Armalite Rifle, not Automatic Rifle or Assault Rifle for the misinformed) as well as caliber conversions, barrel lengths, etc. There are a spectrum of priced AR-15 rifles and receivers, stripped or complete.
For barrels shorter on rifles than 16 inches a BATFE Form 1 along with $200 transfer tax, etc. must be submitted for legal ownership of a short barrel rifle.
In this video:
Tru-glow 1x6.24 scope
Redi-mag magazine accessory
MOE Magpul pistol grip and buttstock
Knight Armament Corporation rail covers.
Magpul magazines
USGI magazines
Surefire magazines
Magpul BAD (Battery Assist Device) lever
Ambidextrous selector lever.
