i got the CA mp5k for my birthday and in my impatience i used rubbish bb's, they exploded in the gun and it is now truely buggered. i opened it up and the piston's teeth and one tooth from one of the gears. i then cleaned out the crap, replaced the piston and gears and greased it up but it still doesn't work all it does is clank a bit when i pull the trigger. if anyone has any idea's on how to fix it please let me know
