This is a promotional film for the Armalite AR-10. This is the 7.62 caliber rifle that led to the M-16 currently used by US forces. It features field-stripping, the belt-fed version, and Eugene Stoner running onto a beach firing from the hip.

The AR-10 was a contender during the 1950's during Army trials to find a new rifle to replace the M1 garand. Some of the other contenders were the M-14 and the FN-FAL rifles, ArmaLite's AR-10 entered the competition late, hurriedly submitting two AR-10 rifles in the fall of 1956 to the United States Army's Springfield Armory for testing. some testers commented that the AR-10 was the best lightweight automatic rifle ever tested by the Armory.

Unfortunately for ArmaLite, the rifle's aluminum/steel composite barrel (an untried prototype design specified for the tests by ArmaLite's president, George Sullivan, over Stoner's vehement objections) burst in a torture test conducted by Springfield Armory in early 1957. ArmaLite quickly replaced it with a conventional steel barrel, but the damage had been done. The final Springfield Armory report advised against adoption of the rifle, stating that "it would take five years or more to take it through tests to adoption".

While rejected by the US Army, limited production of the AR-10 continued. Guatemala, Burma, Italy, Cuba, Sudan and Portugal all purchased AR-10 rifles for limited issue to their military forces.

It is believed that approximately 4-5,000 Portuguese variants were produced; nearly all of them were sold to the Portuguese National Defense Ministry by the Brussels-based arms dealer SIDEM International in 1960. The AR-10 was officially adopted by Portuguese Hunter paratroop (Caçadores Pára-quedista) battalions, and the rifle saw considerable combat service in Portugal's counter-insurgency campaigns in Angola and Mozambique during the 1960's and early 1970's.

Plans to order additional quantities of the AR-10 rifle were stymied after the Netherlands embargoed further shipments of the rifle to Portugal; nevertheless, the AR-10 continued in service with a few Portuguese airborne units, and was in use as late as 1975 in the Portuguese Timor (East Timor) decolonization emergency.

A few Portuguese and Sudanese model AR-10s found their way by various means to nearby African countries; in Chad, the AR-10 was much appreciated by members of French Foreign Legion. As one police instructor in the Congo stated, "It was a good combat weapon that never failed me; a bit too long (but not as bad as the FAL or M-14) for house-to-house work or really heavy brush, but great for 400-800 meters, in the flats - and really nice on the body, after wandering around 12-14 hours looking for bad guys."

Over its production life, the original AR-10 was built in relatively small numbers, with fewer than 10,000 rifles assembled.

The AR-10, extensively modified since the original design, is still manufactured and sold as the "AR-10B" and several other designations. While ArmaLite Inc. holds a US trademark on the name "AR-10", other rifle manufactures currently produce .308 semi-auto rifles that are based on the AR-15/AR-10 design: the DPMS LR-308, KAC SR-25, Rock River Arms LAR-8, American Spirit Arms ASA .308, Fulton Armory Titan, LWRC's R.E.P.R., LaRue Tactical's OBR, RND Manufacturing's "The Edge" and the German Oberland Arms OA-10.