G&P GBB M16VN Roller Bolt Carrier Set A (Negative Pressure) for WA / G&P M4A1 Series

The all new GBB M16VN Roller Bolt Carrier Set A (Negative Pressure) for WA / G&P M4A1 Series is an innovative design that revolutionized the performance of the WA system for those who had G&P M4 GBB(WA) / Western Arms M4A1 GBB series. The overall weight of the bolt has been decreased, and on the back 3 rollers were added to ensure extra smoothness of the bolt travel, both added together means the bolt travels smoother, faster and consumes less gas for each shot, enhancing gas efficiency. Comes with an extra set of nozzle and internal parts for the bolt carrier group (BCG).