Can't believe I didn't recognise it as an Automag!
Sure it's airsoft though? That magazine looks real to me.
Well, I am certain it is not the real steel we have here. Look at the muzzle. Count the vent holes. Look at the grips, too plastic. And finally, the bolt assembly, does not look like real steel at all.
Also finding a few pics of one that looks identical, UNIX 1986 model something. Just can't find any real info about it.
I actually had one of these things back then.
It was soft-air, it used a 'full length' case, in the front of which was placed a soft plastic pellet. . (they looked a lot like a standard .177 Airgun pellet scaled up)
The cases were loaded into the magazine, as the bolt was manually pushed forward it stripped a round and chambered it. (this also compressed the piston)
On pressing the trigger the weapon fired, a second stage on the trigger unlocked the bolt, which came flying back (spring loaded), extracted and ejected the now empty case.