That depends if you are talking about the firearm or about the cartridge.
I believe you are referring to "cartridge." The cartridge is the entire assembly of the bullet, primer, powder charge, and casing.
Cartridge
abbreviation for cartridge
It holds the cartridge in place for firing.
It holds the cartridge in place for firing.
Dimensionally similar, but they are not exactly the same. A firearm with a 5.56x45 chamber can accommodate the .223 Remington cartridge, but a firearm with a .223 Remington chamber cannot accommodate the 5.56x45 cartridge.
Never heard of "ctgf", but "ctg" means cartridge.
For which firearm?
The chamber of a firearm is the part that holds the cartridge when it is in position to be fired.
The cartridge ejector is part of the ejection system in a firearm. This system is responsible for removing the spent cartridge case from the chamber and expelling it out of the gun.
On an airweight Smith & Wesson firearm, or any firearm, "ctg" means cartridge. For example, "38 special ctg" or "38 spl ctg" would mean the firearm fires a 38 special cartridge. Cartridge in reference to firearms means the entire package which carries the projectile or bullet, the powder or propellant charge, and the primer which detonates and ignites the powder. The cartridge case is usually made of brass, or less commonly, steel. Many antique cartridge cases were made of copper. What many people incorrectly call the "bullet" is actually the entire cartridge package.