When the gun stops firing, is the piston in the 'fully cocked' position as in ready to fire? I'm having a similar issue with one of the black JG mechboxes I bought from Huang. I put it in the gun, and it worked great for the first few shots in semi (which returns the piston to its full uncocked position). After firing a few bursts in full auto, it stopped shooting and the fuse blew. Upon disassembling my gun, I found the piston locked fully back. I've had this happen several times to the gun now.
I swapped the stock spring with a Prometheus MS110SP spring, and not having that issue anymore. Having other semi / full auto issues, but that's another story.
__________________
|