If the Marine Corps replaces the M4 with the HK416, the M4/M16 era will come to an end after a 52 year run.
http://www.thefirearmblog.com/blog/2016/11/20/will-marine-corps-replace-m4-hk416-usmc-evaluates-m27-iar-standard-issue-rifle/?utm_source=Newsletter&utm_medium=Email&utm_content=2016-11-22&utm_campaign=Weekly+Newsletter
Whatever happened with the FN SCAR? I thought it was supposed to be the hot ticket for a future M4 replacement.