Which component primarily defines a gas-delayed blowback firearm's operation?

A gas-delayed blowback firearm relies fundamentally on its gas system to manage the operation of the cycling action during firing. In this type of mechanism, a portion of the gas generated from the fired cartridge is redirected to delay the rearward motion of the bolt. This delay is crucial since it allows sufficient time for the pressures within the chamber to drop before the bolt begins its rearward travel, ensuring that the extraction and ejection of the fired cartridge case occur when pressures have lowered to safer levels.

The gas system is engineered to channel the propellant gases from the barrel to a piston or directly to the bolt mechanism, which initiates this delayed action. This method of operation differentiates gas-delayed blowback from direct blowback systems, where the bolt moves immediately upon firing without such mechanisms for gas redirection and pressure management. Understanding this principle highlights the importance of the gas system as the defining component in such firearms.