I couldn't hold out any longer...

[Dust2Dust]

http://media.putfile.com/MOV0126718

It's dark and not really great quality video, but you can see it blowing back.   I used the KWC gas rig with this, that's why you might hear a hissing noise, the connection between the two lines had a weak seal (two tubes, but nothing broke just sprayed gas everywhere).

Ah, gotta love "Soft air" *rolls eys*

[Dust2Dust]

EDIT: Better video of the SP shooting, little dark, but you can see it blowback, as well as a bb nail my 1965 Fender Mustang, grrrrrrr.
http://media.putfile.com/MOV01282
Note: when I'm letting the gas go at the end, it's because I didn't want to disconnect the hose with that much pressure, so I just let it come out of the front.  And yes, I've got it hooked up to redgas


Last gun, maybe
Kokusai M16a2 Carbine with quite a few upgrades:
- Custom anti-rotation collar
- Custom tapped set screw
- 6.03mm Tightbore SCS
- Steel recoil weights
- Brass internals