RA-Tech sent in news that should make owners of the GHK M4 Gas Blowback Rifle series happy. They have now released the RA-Tech SVOBODA AAC 300 Black Out 9in Front + Precision Inner Barrel 6.01 for the GHK M4 GBB. Previously, the kit was made for the WE M4 GBB Rifle, and just like the WE version, it is well made and robust as based on the testing they have done with the set a few months ago.