Airsoft Canada - SIG 552 jamming occaisionally in semi

Ok so it looks like I found the answer.

http://www.airsoftcanada.com/showthread.php?t=87465

Quote:

A problematic situation is the semi-fire lock-up. This can happen if you're trying to rapidly bump-fire your gun. It happens even more often when you fire your gun and the battery is showing some loss of charge due to use. When this happens, simply push up to full-auto. You will be able to fire in full-auto, and typically after firing a few rounds in full auto and going back to semi-auto, you will be able to shoot in semi auto again. This can be annoying at times, but all guns do this at times. If you have a fully charged battery, you will be able to fire quickly on semi auto near flawlessly with minimal seizing. Like all guns, you can't pull the trigger again while the piston cycle is still in motion. If you do that, you'll either not be able to pull the trigger at all on the second shot, or when you pull the trigger on the second shot, nothing will happen. Note that this also happens if you release the trigger too early in the way that you pulled it maybe 1mm back then released it. The next trigger pull you try to make will either fire the round loaded in, and then seize up, or you just won't be able to pull the trigger. In that case, switch to full-auto, fire 3 rounds or so, and go back to semi-auto and you'll be fine (Usually. If you're still seized, just go back to full-auto and fire again and switch back to semi). Basically, don't be an idiot trying to pull the trigger as fast as you can. You'll just cause it to seize up.

Thanks to Rotting for his review!