Pressing: Manufacturing may be one of your biggest expenses. There are a few different ways this can go down: If you have a distribution deal, your distributor may pay for manufacturing up front and then recoup the costs from sales.
When a opening takes place (someone retires) then the Marine Corps promotion board looks at the available candidates and their fitness report scores to fill the vacancy. So make sure you have excellent scores and reports. I picked up SSgt (E6) in 10 years. Gunnery Sergeant (E7) may take up to 14 to 16 years.
Master Gunnery Sergeant/Sergeant Major (E-9) - 10 years TIS and 3 years TIG; The Difference in the USMC E-8 (Master Sergeant and First Sergeant) Master Sergeants and First Sergeants in the Marine Corps are paid the same (both are E-8s). However, the First Sergeant has a much larger degree of authority and responsibility. The First Sergeant wears special rank (with a diamond), and is the top enlisted leader in the unit. First sergeants work directly for the unit commander and are responsible for the morale, welfare, and discipline of all of the enlisted members assigned to the unit.