You probably have a stripped gear. Recently, I've had 3 ICS guns with stripped sector gear teeth. It could be the problem you have here. One of these was the new AK-74M.
Gears for ICS should be easy to get in the U.S. though.
Age verifier Northern Alberta
Democracy is two wolves and a sheep discussing what's for dinner.
Freedom is the wolves limping away while the sheep reloads.
Never confuse freedom with democracy.