Airsoft AR57 Upper for G&G and ICS Bodies

This is my take on the AR-57 for airsoft. The Echo 1 version is hard to find in my area and I really wanted to get one
 This will work with base G&G or ICS Lower Receivers. The handguard offers an M-LOK compatible rail system. 

This project either requires an extended custom nozzle or the nozzle extender to be attached to the existing nozzle. Recommend using a metal nozzle if using the extender to prevent crushing or damaging the existing nozzle. 
if using the nozzle extender you can swap upper receivers as you wish.

This will not work with a gearbox with EBB (electric blow back). The EBB unit is too tall. You will need to get a gearbox without the EBB.

Full STEP files available

Parts needed
(you do not need these specific screw/heat insert kits. but you need the specific spring) Where is each screw used?
The 3 M3x25 is for the top rail on the upper Receiver
The 1 M3X6 hex head is for the hopup retention
The 2 M3X6 countersunk is for the front rail at the front of the handguard
The 4 M4X8 is used to hold the handguard onto the upper receiver
The 2 M4X10 is used to attach the outer barrel to the handguard/upper receiver
all heat inserts are pointed out in the video below

 

Video link for assembly: 
Video says its for the ICS but assembly for G&G is identical