Armalite AR-180B

The original AR-180’s design intended to combine the best of features of the AR-15 (M16) and AK-47.  Alas, it never quite caught on within military circles but it did significantly inspire subsequent rifle development.  This particular copy is a civilian-legal reissue by Armalite, hence AR-180”B”.  This version differs from the original by use of a non-folding stock, a post-ban barrel (20 inch) with integrated muzzle break, polymer lower receiver, and the ability to use AR-15 magazines.  The trigger group and bolt are pirated from the AR-15 as well.  It is chambered in 5.56 x 45 mm NATO (.223 Remington), and has a non-adjustable short-stroke piston gas system.  Magazines are 30-round steel rather than aluminum.  The rear sights have two apertures, one for ranges between 0 to 250 yards and the other for ranges beyond 250 yards, but they have not yet been properly zeroed.