Disclosed is a cartridge case for various caliber ammunition that can consist essentially of a powdered metal and/or powdered metal alloy(s) that is formed into the cartridge case through an injection mold processing. Also disclosed is a method for forming a cartridge case, which may include use of Metal Injection Molding (“MIM”) processes to produce the cartridge case which retains a primer, propellant, and/or a bullet. Also disclosed are embodiments related to a case telescoped cartridge that may include a cap and a body. The body can consist essentially of or consists entirely of a powdered metal and/or powdered metal alloy(s) that has been formed through MIM. The cap can comprise plastic that has been formed through plastic molding or comprise powdered metal and/or powdered metal alloy(s) that has been formed through MIM.