Spectre Airsoft has this quick review of the FCW 400-Roundd Gas Drum Magazine that can be used with the Tokyo Marui MWS Gas Blowback Series... "Hey guys today I'll be doing a quick review of the FCW (Flintlock Custom Works) 400'Rd Gas Drum mag from Flintlock Custom Works/ Octagon Airsoft. Overall review of this drum mag, is that runs really well, feeds wonderfully, it can feed the 400 rds. no problems and with plenty of gas left in the tank!