@StagateSg7
Please correct me if I'm wrong - and no need to shout if you do, by the way - but don't American weapons fire those dinky little 5.56mmN rounds, not 7.62mmN? I guess a few units might have the odd M60 or Stoner M23 laying around but I didn't think they really bothered with anything between the SAW/Minimi and the Ma Deuce these days...
Besides, why bother with silly old projectile weapons when they have all those alien-supplied laser weapons and Man-Portable Fusion- and Plasma Guns?