I have a jg g36c which i have just upgraded with the following:
SHS M110 spring-http://www.amazon.com/gp/product/B0054MKG9E/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
SHS 7mm metal bushings-http://www.amazon.com/gp/product/B005152J30/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Raptor RTQ 7 steel teeth piston-http://www.amazon.com/gp/product/B00JZJ4DKK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Element Piston head-http://www.amazon.com/gp/product/B007FHH2OI/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
SHS Ball Bearing Spring Guide-http://www.amazon.com/gp/product/B0055T9MI2/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
I insalled all of these shimmed correctly there is a very tiny amount of play. I greased everything perfectly with madbull grease and lube. After I had closed it and made my first shot, i pressed the trigger and it cycles all the way back but doesnt release. I explored a little bit and saw that the new spring is longer by about one inch(old spring was stuck to the piston head from the inside on purpouse), and the new piston and head in total was about 2 mm longer than the original piston and head.
So should I sand some of the old piston from the bottom so that it can move more back(bad wording lol) and have space for the gun to complete its cycle?