Honestly, I'd rather carry a bullpup configuration on the modern battlefield. Combat has become increasingly an urban short-medium range affair and trying to swing around a huge M-16 inside of a humvee is a hell of a lot harder than bringing an AUG or Einfled or SAR-21 to bear on an enemy.
You can have the best ammunition and have 5x better accuracy than your oponenet, but if your enemy can get off 5 shots before your barrel levels at him. You're dead.