GHK M4 Gas Blowback Rifle owners will stop enying the WE M4 GBB owners who have got the forged receiver from RA-Tech. Previously, they announced that they will be producing the forged receiver for the GHK M4 GBBR and this video shows the prototype. We are given walkthrough of the receiver with the internals being stock GHK M4 GBB internals and also a test fire.