Just a heads up, Greg (Chef/Jackals) had some problems after a while on the game Saturday, he said it was making a funny noise but still shooting BBs. I just dropped it off, I dry fired it, got two good bursts out of it then it stopped, could only hear the gears spinning. I figured it was a blown piston (he's famous for that now, this would be the third AEG with that problem). Mechbox is a royal bastard to get out BTW.
Anyways, I got the mechbox open, the bevel gear teeth where it meshes with the spur gear sheared off. Explains why it's still fire while making that noise, then fire when I tried it only to find gear noise and no bang.
So, am not sure the reason, it was bone stock when this happened. He's looking for gears now, but I suggested he buy a new piston as well since CA makes the shittiest pistons out there. I suggest anyone else replace the piston AND the piston head when they decide to crawl into their mechbox, it'll make it more reliable (stock TM parts ARE surprisingly good, in all honesty I've had less problems with stock TM parts than I have with seeing aftermarket parts blow or cause problems.)