Hi: here there are a lot of pics. of the Hatsan Quattro trigger. It's supposed to be standard on all Hatsan newer rifles, except the basic models 33 and 35, however I don't know which of them come to the USA and in what "dress"...
The trigger unit, different views (note: the yellowish thing is a piece of wood I put to keep springs under tension and avoid loose pins).
We begin the disassembly. This is very easy since all pins are free to move (no rivets). Remove the bigger pin that holds the "main sear" (the one that holds the piston):
Then remove the pin that holds the "intermediate sear # 1" (this one engages with the main sear). Now both, main sear and intermediate sear # 1, which are joined by a spring, can be removed:
Next remove the pin that holds the trigger blade:
Next remove the pin that holds what I will call the "pressure spring vise":
And finally remove the "intermediate sear # 2" (this one engages with the intermediate sear # 1):
Disassembly is now complete. There is a remaining pin in the cassette, which is secured by an e-clip, this is not necessary to remove.
Now, different views of the cassette. Some have said this is rougher than the cassette of the Rekord trigger, but I would have to disagree: it looks and feels about equal:
Now a close-up of the different components. I am as ignorant as a human being could be about metal/metalworking, but from the pure looks these seem very well done (no stamped-sheet metal parts):
The trigger blade seems to be made from a softer cast-metal, as it is the pretty much the norm. However, it is a piece that looks far more complex to build than the Rekord trigger blade, having two adjusting screws, a nylon insert to keep them tight, and two strange "wings", which probably serve the safety/antibeartrap function of the gun. AFAIK, the finish options for this blade are a black paint and gold-plated. In this aspect the Rekord trigger blade wins, it has a much nicer finish and feel:
This bag is to be found on the box of the gun:
As it becomes evident from watching the parts, the adjustments are as follows (the manual is quite vague on this).
The screw that is more forward on the trigger blade, adjusts the total length of sear engagement (engagement of intermediate sear # 1 and intermediate sear # 2), that is, the sum of the lengths of stages 1 and 2. Clockwise you reduce this length. Anti-clockwise you increase this length. You will have to use this if you want to adjust to length of the first stage of the trigger to a specific desired value (but note: you will have to use the screw that is rearwards, in conjunction):
The screw that is more rearward on the trigger blade, adjusts the point of limit between the first stage and the second stage of the trigger. Clockwise you increase the length of the second stage. Anti-clockwise you reduce the length of the second stage:
The screw that is on the "pressure spring vise", adjusts -obviously- the pressure of pull of the trigger (both stages). Clockwise you increase the pressure and anti-clockwise you reduce the pressure:
However, given the fact that the main sear and the intermediate sear # 1 are joined by a strong spring, the pressure spring adjustment seems not to produce the desired results (incl. consistency), when too little pressure is set on it. Some have said you can solve this issue if you replace the spring that joints the main sear and the intermediate sear # 1 with a weaker one, and if you polish/hone the contact parts. I haven't tried this recipe yet.
Now let us assemble the parts outside the cassette, and engage the trigger, to see all in operation:
The trigger blade is moved from the rest position to the second stage just before firing: