Also known as: HK416
An AR-15-style 5.56×45mm NATO Assault Rifle made by Heckler & Koch, introduced in 2004. Looks a lot like the M4 Carbine but has a railed forearm with folding front sight and internal changes. The HK416 uses a proprietary short-stroke gas piston system from the G36. It can be outfitted with a variety of barrels, ranging from 228-505mm in length.