Heckler & Koch MG4 machine gun.

The geometry is two kinds ,parts that are meant to be subdivided by a turbosmooth modifier instanced between them, and the remaining parts stay as they are. Turbosmooth iterations should be at 2 for best quality, in close up shots. For away shots, even at 0 iterations there is no noticeable change in quality.

The moving parts of the gun are pivoted correctly so they can be rotated to make the gun "fold up" to be carried by a trooper.

-stock folds up
-front sights fold down
-carry handle opens up
-casing exit door closes
-stand legs open up and extend

the ammo belt is rigged with spline ik, so by selecting the first bullet (name: bullet) and changing the amount "% Along path" in the animation tab, the bullets move along the belt and enter the chamber.

Texture resolutions :
2048x2048
1024x1024
512x512