What rank is identified by the insignia of 3 chevrons above an exploding bomb above 4 rockers?

The rank that is identified by the insignia of three chevrons above an exploding bomb and four rockers is indeed Master Gunnery Sergeant (MGySgt). This insignia reflects the rank structure of the Marine Corps, where the three chevrons represent the non-commissioned rank of sergeant, while the bomb and rockers indicate a higher level of responsibility and experience. The addition of the four rockers signifies that this rank is among the highest enlisted ranks, correlating directly to the concerns of leadership and expertise in technical and tactical subjects.

The insignia clearly distinguishes the Master Gunnery Sergeant from other ranks, such as Sergeant Major, First Sergeant, and Brigadier General, which have different symbols and insignia designs reflecting their unique roles within the military hierarchy. Understanding these details helps in recognizing the significance of this rank and its responsibilities within the Marine Corps.