It wouldn't be something so obvious as that the pitch treading is generally CCW for Tokyo Marui compatable Mp5's, would it be? No leftie-loosey.
If you've screwed it up beyond all recognition, have no fear, redemption is here.
http://www.airsoftparts.ca/store2/in...roducts_id=911
But I'd go this route.. looks meaner. (I did.)
http://www.airsoftparts.ca/store2/index.php?main_page=product_info&cPath=67_102&prod ucts_id=968