This paper model is a full size Heckler & Koch G36C, a variant of the Heckler & Koch G36, which is a 5.56×45mm assault rifle, designed in the early 1990s by Heckler & Koch in Germany as a replacement for the heavier 7.62mm G3 battle rifle, the paper model is created by Vitold Vessone. The size of finished model is about 294 (H) x 56 (W) x 720 (D) mm.
The G36C (C="Compact", commonly mistaken for "Commando", a term trademarked by Colt Firearms for the CAR-15) subcarbine model is a further development of the G36K. It has a shorter barrel than the G36K, and a four-prong open-type flash hider or a birdcage type flash hider. The extremely short barrel forced designers to move the gas block closer to the muzzle end and reduce the length of the gas piston operating rod.
The handguard and stock were also shortened and the fixed carry handle (with optics) was replaced with a carrying handle with an integrated MIL-STD-1913 Picatinny rail. The dual optical sight found on the standard G36 and G36K models was replaced with a set of rail-mounted detachable iron sights that consist of a semi-shrouded front post and a flip-up rear sight with two apertures of different diameter. [Source: wikipedia]