Originally Posted by
a0cake
Considering that ELCAN Spectre DR 1-4's, 1.5-6's, ACOG'S, and soon the Squad Common Optic (probably going to wind up a 1-6 or 1-8) are all readily available to anyone who wants one on their M4, there is no point in adding 1.5'' in barrel length, the same kind of optics, and calling it something else. More accurate ammunition for the M4's would provide 99% of the capability.
It's about echelons of capability. An accurized 5.56 platform is all well and good (and can be used with great results), but if you want to elevate capability by an order of magnitude, a 7.62 platform is where you'll make your money.
Honestly your first question, "would 5.56 be preferred in a MOUT setting" is odd to me. Obviously 5.56 is preferred if you have to go house to house. But not everybody in the unit can have the weapon that is most advantageous for every setting. There needs to be a wide range of capabilities, from individual weapons to crew served weapons. Proper planning based on METT-TC will allow for the most advantageous distribution of various weapons systems in the ground tactical plan / scheme of maneuver. Support / Assault teams etc. etc etc. I don't think nerfing the precision rifle capability by making it a 5.56 to suit a MOUT setting, at the expense of the advantages that a DM can provide at intermediate and long range is wise. There are plenty of M4's on the ground.