Which of the following is NOT a type of gun action?

The term "repetitive" is not recognized as a standard type of gun action in the context of firearms. The common types of gun actions include semi-automatic, pump, and bolt actions, each describing a specific mechanism for loading and firing ammunition.

Semi-automatic actions allow for one round to be fired with each pull of the trigger, automatically ejecting the spent casing and chambering the next round without requiring the shooter to manually cycle the action. Pump actions require the shooter to manually slide a forearm back and forth to eject a spent shell and load another round. Bolt actions involve manually operating a bolt to load and chamber a round after each shot is fired.

These mechanisms are essential for understanding how different firearms operate and their functionalities in hunting and shooting scenarios. In contrast, "repetitive" does not align with established terminology, making it clear that it is not a type of gun action.