What does a Master Gunnery Sergeant do?

I've been thinking about joining the Marines and I came across the role of a Master Gunnery Sergeant. Can anyone explain what their job responsibilities include and how they fit into the overall structure of the Marine Corps? Thanks!

In the U.S. Marine Corps, a Master Gunnery Sergeant (MGySgt) holds one of the highest enlisted ranks. The MGySgt falls just underneath the ranking of Sergeant Major and forms a key part of the senior enlisted grade.

Their role is two-fold: they hold leadership positions and are subject matter experts in their chosen occupational field. Unlike other military leader roles, a Master Gunnery Sergeant does not hold a command authority position, instead focusing intently on their specialty training.

For instance, a MGySgt in an infantry unit might be specialized in particular combat strategies, weapons systems, or tactical scenarios. In contrast, a MGySgt in maintenance bay would be an expert on aircraft repair and maintenance.

A key part of the MGySgt's role is to advise lower ranking officers and enlisted Marines in their area of expertise. They guide, mentor and train these members, ensuring competent performance across their specialty.

In summary, a Master Gunnery Sergeant's role is geared towards deeply skilled, professional expertise and advising within a particular field. They do not hold command roles in the same sense as a Sergeant Major, but they are essential to maintaining operational excellence and high-performance within their occupational specialties.