I picked up some mags with an order and found they were tight. The front section locked in place but the rear tang that locks in the mag catch was too bulky.
This was easily remidied with a cold chisel taking off about 1mm of material and voila. About a 2min. job for each mag.
Fyi: The JG hop unit is an exact copy of the TM unit which is tapered. These may be easier to source than the TM units.
Another thing I did was removed the washer at the barrelassembly. (when you remove the barrel in the ICS you'll know what I mean).
I found it was binding against the TM hop unit making it more dificult to turn.
Maybe I forgot to eat my Wheaties but it seems more willing to turn know.
Canīt sleep. Clowns will eat me!