Abstract: A delayed blowback system for a firearm is provided. The system includes a bolt with two detent members operatively coupled within the bolt, each detent member comprising a detent. The system further includes a recoil spring guide rod having two matching recesses on opposing sides of the recoil spring guide rod, wherein the bolt and the two detent members are coupled to and slidable along the recoil spring guide rod between a firing position and a recoil position. The firing position includes the detents resting in the matching recesses on the recoil spring guide rod in response to a round being fired, the bolt moves back and pushes the detent members back, wherein by nature of a geometry of the detents and the matched recesses, the detent members outward in opposite directions and perpendicular sliding along the recoil spring guide rail in the recoil position to complete a recoil cycle.