Rifle maker ArmaLite put together a chart schooling those not already in-the-know as to just what the “AR” in AR-15 stands for as well as touching base on some of the rest of the family tree.
For the record, the company started in Hollywood of all places in 1954 as a division of the Fairchild Engine and Airplane Company and their first rifle, the 6-pound (with scope and sling) AR-1 Parasniper (ArmaLite Rifle-1) was a .308 that would only populate Army museums. They went on to make the AR-5 and AR-7 Explorer survival rifles before the 7.62x51mm AR-10 came along.
Then of course there was that AR-15 gun and, after the company sold the rights for that to Colt, came the AR-17 semi-auto shotgun (it had a gold finish with an aluminum barrel– no fooling) and the AR-18/180 before the company folded its Costa Mesa location in 1973.
Eagle Arms picked up the rights and trademarks in 1995 and carries on as ArmaLite today, based out of Geneseo, Ill. and has since introduced the AR-20, 30, 50 et.al.