Ok so I recently upgraded my tm m4a1 mechbox with the following:
Piston Head: SystemA Silicon Piston Head w/Bearing
Cylinder Head: Guarder
Nozzle: SystemA
Spring Guide: SystemA w/ Bearings
Spring: PDI 120 & soon a Prometheus MS100SP
Inner Barrel Prometheus 6.03mm BS (363mm)
Hop Up: G&P Metal
This was my first time tearing the mechbox apart but I did alot of research with mechbox.com and other sources. Ok so i spent about an hour to properly shim it(i used
http://www.geocities.com/wajoegween/aegshim.htm as a guide). So I put it all together and it seems to shoot fine with zero misfeeds or other problems(~400 rounds). Now the only concern is that when i fire i hear a faint "springy" sound after every shot. Its hard to describe... Like a spring vibrating... ok so i think it might be the gears but you guys are the experts! Any ideas? Should i be concerned for my MechBox blowing up anytime soon?