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.
Gunnery Sergeants in infantry and combat support units (i.e., all other Ground Combat Element organizations) typically serve in the billet of Company (or Battery) Gunnery Sergeant or as the Platoon Sergeant of a crew-served weapons platoon (i.e., machine guns, mortars, assault weapons/rockets, and anti-tank missiles) or Platoon Sergeant and/or ...