VFC BCM MCMR 11.5" GBBR (Black)No Compromise? GET VFC! Improved Lower Receiver Internal Structure VFC BCM MCMR 11. 5" GBBR is not only directly put into the new design "Non cut lever" Steel Hammer Set, but also improve the structure of the lower receiver, increase the fitting depth, and the structure of the firing pin base parts is greatly simplified, making the valve knocking action more stable, the durability of the parts is effectively improved, and the maintenance will be