Does anyone know the difference; what they do, etc.? I was in the Marines back in the mid 70’s, and I don’t remember the rank “Master Gunnery Sergeant.” It is recent, or just rare in those days (or in my battalion).
From Wiki: One of the major differences between the two E-9 ranks is that master gunnery sergeants retain their Military Occupational Specialty (MOS), while sergeants major are given a new MOS to reflect their general command focus. This reinforces the master gunnery sergeant’s role as a provider of technical military leadership.
Sounds about right to me. The senior player in the Marine Band saxophone section holds the rank of MGSgt (the other 3 are MSgts). The man plays one of the most beautiful-sounding tenor saxes I ever heard.