I'm all for shot placement and it holds true when you have a visible target that your shooting at. However, my problem with the 5.56 comes when you have to engage a target that is behind concealment or even lite cover.
There was a video I saw once that I'm sure some of you guys have seen. This guy basically shot a lot of different guns and a lot of different ammo to show the effects that rounds had on certain materials and the effect that certain materials had on the round. Anyway, this guy shot an M-16, loaded with the M855 round through a stand with leaves and twigs on it with a target just 1 foot behind it. The guy shot three rounds from a pretty short distance aiming at the center of the stand, the bullets were deflected so much that one of them barely even hit the target and the other two were off center buy almost 9 inches. The same test was preformed with a 7.62, and while the rounds were slightly off they were all more or less on target.
Similar test were preformed to show the effects the round had on cinder blocks, solid wood, and bricks. Each time the 7.62 out performed the 5.56. To me that is a factor that is very important when your talking about MOUT or even working in a jungle or wooded environment. It would really suck if you know there is a guy behind a thick bush, or a guy that you know is right next to a window but you can't nail his ass because your bullet either won't penetrate or is deflected to far to have effects on target.
Don't get me wrong, obviously the 5.56 is a lethal round; however, like Paradus said the 5.56 is not the ideal all purpose round that it is cracked up to be. Also as far as shot placement goes its all well and good at 25 or 30 yards. However, in a combat situation using iron sights with a target 100 to 150 yards away, your heart pumping, sweat and dirt in your eyes and the other guy shooting back hitting him or her in the heart or in the upper center of the face is easier said than done. I'd like to see a round that will put someone on their ass rather you hit them in the stomach or dead center in their chest, and will do it with one shot not three four or five. Personally I believe that the 6.8 is worth the military taking a real close look at. Just my :2c: