Here's a new video from RA-Tech showing a prototype M4 CQB airsoft gun kitted with MOE furniture. There is no mention of what type of airsoft gun this is, especially its power source. But we assume that it's a gas blowback since RA-Tech especialises more on gas blowbacks. But we can be wrong here. Another assumption here is the test is not just a shooting test, but an actual skirmish test as shown in the photos.