I guess this is my bottom line feeling on the issue. Its time to design a new rifle from the ground up. Screw improving existing platforms and adapting this and that. Screw searching for the perfect caliber for the same platform. Put a bunch of smart guys in a room. Grunts, gunsmiths, science guys. Give them three parameters.
1 realiabilty under extreme conditions with minimumal maintainence and maximum simplicity (Glock being the model here)
2 adequate knokdown power and still relatively light weight
3 +/- 3 moa at 300 yards.
Then give them a blank sheet of paper and as much money as they need, and a mandate to come up with something new. Thats the way we did it in WWII. The Pentegon foots the bill, directly or indirectly, says here's what we need, impress us. There is no reason to use an almost fifty year old rifle as our MBR. Come up with a new concept. We have done this before, and its a lot cheaper and more useful than the new air superiorty fighter jet (Which we will fly against who? When?).
FQ13