SayUncle reports on this. Apparently it’s a very realistic version of the M4. I found a site that sells and demonstrates this Airsoft gun here. It would seem to have all the pin holes in the right place for accepting an M16 fire control group. Not saying it does, because it’s difficult to tell without taking measurements, but if it accepts those parts, plus a standard M16 or M4 upper, it’s effectively an M16 lower receiver, and would be considered a machine gun under the law.
Another video here, which seems to show extra junk in the lower, but it’s hard to tell if it would come out, or is a permanent part of the lower. I’m skeptical that you could punch out the Airsoft fire control on this and drop in an M16 fire control group without any modifications, but it’s really hard to tell without having one in hand to look at. Here’s a close up of the lower.
What do you think? I’m particularly interested in hearing from people who have experience with M16 lowers.