So I recently finished upgrading my G36c and I took it to a battle with my friends. Instead of working perfectly as planned, every 10-20 shots it would pull the piston to the last tooth and stop right there. It's as if the motor just can't quite pull the spring all the way. I don't think the reason is the motor, because I tried two different motors on the gearbox. (both the stock motor and a Tokyo marui EG500) Also, I tried both an 8.4v and 9.6v battery with it.