I found out where all the .308 went
Lance Cpl. Michael Rogers used it all:

PACIFIC OCEAN (May 22, 2009) Lance Cpl. Michael Rogers awaits instruction after firing an M-240B machine gun during a live-fire exercise aboard the aircraft carrier USS George Washington (CVN 73). Marines from Fleet Anti-Terrorism Security Team Pacific (FASTPAC) are conducting training with George Washington security forces. George Washington, the Navy's only permanently forward deployed aircraft carrier, is underway conducting a combat operations efficiency evaluation in the western Pacific Ocean. (U.S. Navy photo by Mass Communication Specialist Seaman Apprentice Rachel N. Clayton/Released)

Not entirely.
I have the rest.
[...] Where all the 308 went [...]
I’ll take care of that brass for you, Cpl!
You guys can have the brass as long as Michael Rogers comes home to me. (: I’m so proud of my marine. (: