American Tactical ALPHA MAXX 5.56 NATO AR-15 Rifle, 16\" Barrel - ATIGAX55613ML: We are proud to introduce the American Tactical ALPHA MAXX AR-15 Rifle - This rifle features the new Gen 2 Alpha Maxx Receiver with an upgraded combination of carbon fiber, steel, and polymers resulting in ATI\'s strongest and most durable receiver to date. This Alpha Maxx model features a fully patented metal reinforced polymer upper and Gen 2 lower receiver group. The Alpha Maxx lower features a patented hammer and trigger pin retainment system which prevents movement from the hammer and trigger pin during firing. It also features ATIs patented over-molded metal insert, which reinforces the buffer tube housing and rear takedown pin. This allows for metal-on-metal contact with both the buffer tube as well as the rear takedown pin, thus increasing strength and durability from recoil and consistent firing. This model also features a 16\" black nitride barrel and a unique patent pending 13\" M-Lok rail. Stock is A-2 style 6 position with a Q.D. attachment. Each rifle ships with a 30 round ATI magazine. The design and style make this one of my favorite ATI rifles yet.