If you look closely, you will see that the weapon itself if very nicely oiled.
I'm afraid to say, this is a navy problem, not the young marine standing there!
It's a squid, not a Jarhead, manning the gun. Still, lousy shape for the mount to be in and the ammo looks damn scary.
No GMC worth his salt would ever let a mount deteriorate into that state.
That's a sailor, not a Marine. Draftsman 2nd Class Arturo Chavez according to the caption. If he was a Marine, LadyX would personally be out there chewing on him, and Texas Cowboy would be haunting his a$$.