Originally Posted by MoreToasties
The model I tried's mock bolt kept getting stuck open when I tried to access the hopup, but that is my only complaint.
For all SRC Gen III M4 / 416 line AEG's, the mock bolt is intentionally made to remain open even after charging handle is let go.
SRC did this to allow "one handed hop up adjustment". After adjusting your hopup, just give the charging handle a push, and the bolt will go completely forward
I do find this design inaccurate with the real gun design, but none the less it does make hop up adjustment a tad more convenient.