M4 Carbine Assault rifle

The M4 Carbine is a lighter and shorter variant of the M16A2 assault rifle. The two have roughly 80% of their parts in common. The M4 carbine family is based on earlier carbine versions of the M16, which were in turn based on the AR-15 designed by Eugene Stoner and manufactured by ArmaLite.

Video on Creative Commons Licence
From:
https://www.youtube.com/watch?v=Itn6IRuV3jc