I am a squid (Navy) and I clearly remember the day the trees (Marines) returned to the ship after their first of many forays into the Afghan hills. I remember them almost begging us to trade our ship's M-14's for their M-16A2's. They were regularly engaged by and engaging the enemy at distances of 500yrds and beyond. They werent getting very good results even with aimed shots using the 5.56. The 6.8mm will be a better round when in that kind of an enviornment definitely. But in my opinion, the 5.56 still has a definite role in the arsenal when we are talking about urban/city enviornments like those that are being encountered in the streets of Iraqi cities.