I believe intermediate cartridges are the way to go, 308 recoils too ahrd for close range full auto, 556 just can't make the long shots. 6.5/6.8 cartridges are looking promising. The AR is over hyped, I have freinds who were told the m16 is the ultimate rifle all through basic and hate the thing. One was told an m4 with ACOG is a better DMR than an m21
