Gunnery Sergeant (UNSC)

Gunnery Sergeant is the seventh enlisted rank of the UNSC Marine Corps, and is a non-commissioned officer. It is equal to the rank of Chief Petty Officer in the UNSC Navy and a Sergeant First Class in the UNSC Army. They are above Staff Sergeant and below Master Sergeant.

Gunnery Sergeants are commonly referred to by the informal abbreviation "Gunny." This nickname is generally acceptable for use in all situations except formal and ceremonial ones. Use of the term by lower-ranking personnel, however, remains at the Gunnery Sergeant's discretion.

Promotion
In the United States Marine Corps, eligible Gunnery Sergeants indicate whether they wish to be considered for promotion to Master Sergeant or First Sergeant, and thus whether they enter the promotional track for Master Gunnery Sergeant or Sergeant Major. Once promoted, the promotional track is permanent; lateral movement between the two programs is not possible.

One of the major differences between the two ranks is that First Sergeants/Sergeant Majors have a general command status, while a Master Sergeant/Master Gunnery Sergeant's role is as a provider of technical military leadership.

Whether this remains the same for the UNSC Marine Corps is unconfirmed.

Responsibilities
In the USMC, a Gunnery Sergeant typically serves as the senior NCO for platoon sized units. They serve as assistants and advisers for Lieutenants. It is highly probable the same responsibilities carry over to the UNSC Gunnery Sergeants, but this is unconfirmed.