Engagements in A-Stan have commonly begun at around 500 yards, and sometimes more. The 7.62x51 M14 has an effective range of 800 yards, the 5.56 M4 is good to about 500 yards. SOCOM troops have more options to adapt to mission specifics than infantry (you won't typically find a pile of M14s in an infantry arms room). A-Stan has been, possibly, the longest distance situation our small arms and troops have ever been involved in.
I know that you know this, but I don't know if other casual readers are aware of these things.