ThisIan of Bunny Workshop reviews the latest M4 Gas Blowback rifle from Tokyo Marui that they now have available at their online store, the Tokyo Marui M4A1 CQBR Block1 MWS Gas Blowback Rifle... "Every parts of this Rifle are designed to resist to the blowback recoil. The Z-System enhanced the durability of the bolt catch, the piston absorber and the friction relief bolt roller minimize the impact of the bolt's cycle on internal parts, the barrel clamp gives more stability to the barrel and help to keep the barrel screw tightened."