Ares Amoeba M4 AM-008 Quick Spring Change System

[apsims]

I'm having trouble accessing the suppossed Quick Change system of the gun. This particluar version of the M4 holds the stock on using a 80mm screw which you access by removing the stock from the stock arm (no castle nut). An earlier video posted by Ares shows the QC system working by just using an allen key, pushing down on the spring retainer and turning the retainer - https://www.youtube.com/watch?v=5SLvS7e8BXo

All the retainer screw does is spin

I'm wanting to change the spring because it shoots at 400fps out of the box.

 

AM-008 Expose reference:

For reference the gun and site I got it from - http://www.onlybbguns.co.uk/ares-am-008-amoeba-ares-m4-ares-am-008-aeg-carbine-efcs-metal-gearbox.html#.VAr6AhZmNAf

 

[SimonQuigley]

I've the same problem, i think the only way to access that panel at the back is to completely remove the gearbox from the reciever and do it that way, shouldn't be called quick change really.