Owners of the Tokyo Marui M4A1 MWS Gas Blowback may want to take watch this video by Nugentgl showing the Spear Arms Barrel Nut Adapter made for it. This is made of steel and CNC machined designed for solid installation of the barrel nut and outer barrel and for those who want a secure fit when installing another rail system on the MWS.

In stock right now at eHobby Asia is the Spear Arms Tokyo Marui M4A1 MWS Barrel Nut Adapter so you can install other rail systems on it... "The Spear Arms CNC Steel Barrel Nut Adapter for Marui M4A1 GBB Rifle is constructed of steel material. It gives a secure and solid installation of the barrel nut & outer barrel.