The barrel and the Hop-Up chamber

Access to the chamber is obtained after pulling it into the outer barrel. This is done in a typical way, by unscrewing the 2 screws securing the chamber and the barrel end. The photo also show the inner barrel stabilizer.

The Hop-Up chamber design does not differ significantly from the TM chamber design.

The bucking is a standard used in the VSR system. The next photo shows the inside of the chamber.

The pneumatic system

Its components work properly, but the plastic spring guide and monolithic piston should be replaced when planning an upgrade. Both components work with a spring with an internal diameter of 7 mm and one should also bear that in mind. 

The trigger mechanism

The factory trigger mechanism consist of levers and latches made of aluminum alloy placed in a housing of the same material. On the right is a traditional, for the VSR series, safety. The trigger has no adjustment and movable parts have no bearings.

Finally, let me remind you that in the description of the Action Army T10 replica by Egzul, which I encourage you to read, you will find, among other thins, a description of a fast and inexpensive tuning, which gave unexpectedly good results. The link can be found under this text.