My M4 is deciding to throw a temper tantrum now, because I upgraded my P90, and didn't buy her any new accessories. She won't lob the BB's more than 50 feet now, and even SHORTER, if I turn up the hop-up.
I've pulled the upper reciever off, and it seems to be putting out plenty of air through the air nozzle... I don't wan't to have to replace the piston, though. I know its not the hop-up bucking/nub, or the air nozzle, because all 3 of those are practically brand new (less than 6,000 rounds through em).
The only thing I've done recently is re-lubed the gearbox, and I made sure not to use too much or too little.
Any and all advice (besides buying a new gun) is welcome. I love my '07/'08 JG M4 to death!
~Brian