Due to the restricted chamber space and the substantial tube inside diameter required for brush clearance, the use of a chamber sealing O-ring is not feasible. To address this, a front brass bushing has been integrated, which centers the guide within the barrel extension and aligns with the chamber opening. Additionally, a large O-ring at the rear end secures into the bolt opening at the back of the receiver, minimizing longitudinal movement of the guide during the cleaning process.