Magpul PTS with Spartan Imports has developed a GBB conversion kit for the AEG PTS ACR/MASADA. The conversion kit is a lower reciever, bolt assembly, hop up, inner barrel, and outer barrel. The magazine is Western Arms compatible. It does not come with a magazine ; You must buy it seperately, but they are widely availabe in this system. Also, the internal parts such as the trigger group, carrier group, etc, are not expected to be WA compatible. The projected release date is 4-6 weeks from Janurary 16th. ( Late Feburary ).
Some people are speculating that Magpul PTS will be releasing a complete GBB rifle which does not need to be converted.