A firearm for firing cased telescoped (CT) ammunition cartridges that includes a split chamber configured to fully support a CT cartridge when it is fired, and that includes i) a dynamic rear chamber portion defining a pocket in a face of a bolt, and ii) a static front chamber portion that is integral to the barrel and separate from the bolt. A cartridge extraction mechanism engages the CT cartridge prior to the CT cartridge being fired, and holds the CT cartridge in the pocket in the bolt face as the bolt moves rearward to pull the CT cartridge out of the static front chamber portion and into an ejection position. An ejector is operable to eject the CT cartridge from the pocket in the face of the bolt when the CT cartridge reaches the ejection position.