User:MJBurrage/USrank2

Sergent (E-7)
A Sergeant First Class (U.S. Army) and a Gunnery Sergeant (U.S. Marine Corps) are the same rank (U.S. code E-7).

They rank above a Staff Sergeant (E-6) and below a Master Sergeant (E-8), which use the same names in both services.

They are equivalent in rank to a Chief Petty Officer.

U.S.A.F.
In the United States Air Force, Staff Sergeants (E-5) and Master Sergeants (E-7) are one grade below the Army/Marine ranks of the same names.

Sergeant Major (E-9)
A Sergeant Major (E-9) ranks above a Master Sergeant (E-8), in both the U.S. Army, and the U.S. Marine Corps.

They are equivalent in rank to a Master Chief Petty Officer.

Background
These ranks have not been used yet in Star Trek, but thier continued existence is implied through the use of the related ranks linked to above.