This is an excellent example of an original and very scarce full-automatic Armalite AR-18 rifle as manufactured by Armalite in Costa Mesa, California. These rifles have similar features to the Colt Model 16 series of weapons and use the same basic rotary bolt system with eight front locking lugs but with a much better piston system that employs a long rod to cycle the action very similar to the FNFAL rifles. This style of gas system was rejected by the military in the late 1950s early 1960s in favor of the gas operated, blow back system developed by Colt for the AR-15 rifles as being lighter weight with less moving parts. However, within many circles in the military today there is a large movement to go to a short-stroke gas piston system similar to this rifle. The receiver is marked " ARMALITE. INC./ COSTA MESA. CALIF./U.S.A." and has an ambidextrous marking and lever on both sides of the receiver marked: "SAFE, SEMI, AUTO" and it is fitted with the black plastic stock components and side-folding buttstock. It has the two position rear sight that is adjustable for windage with a post front sight also adjustable for elevation. It also features an aluminum heat shield inside the handguard, three prong flash hider, bayonet lug and a sheet metal stamped upper and lower receiver. It is complete with five original Armalite AR-18 marked magazines and a scarce Armalite marked 2.75X power scope.