In the movie Enemy at the Gates about the battle of Stalingrad at the beginning of the movie fresh consripts make a daring river ccrossing only to find a big truck and officers shouting at them "The one with the rifle shoots, the one with the ammo follows, when the one with the rifle is killed, the one with the ammo picks up the rifle and shoots!" and handing out said rifles or a single stripper clip to any particular soldier. Did that actually happen?