[Magnum]

As I recall from the book, they had resupply throughout the whole time. They also had constant air support from the little birds. It was much more than that one big fire mission they showed at the end of the movie.

As for the M-14: Everybody was carrying M-16s with new armor piercing ammo. The problem was that the bullets would go through the target and it would require several shots to bring a guy down. He was using the M-14 because it fired a heavy bullet that guaranteed a one-shot kill. Being the highly trained Delta commando that he was, he could make each shot count just as easily with any weapon, so he made a wise choice in terms of stopping power. Of course, with the volume of targets, he would've done just as well to have a flamethrower or Vulcan gatling gun. (OK, sorry for the exaggeration there.)