Other than the Sig being as heavy as a M1A Socom, how does it match up to a COlt M4? How many yards is the Sig 556 good for? What size groups at what range? Does the Sig run as well as an AK with abuse? How does the 10 inch SBR compare to a 10 inch M4. The weak link in an M4 is long term reliability, wearkest in an ak is range, does a sig fill the gap?