I detail stripped one of my VP9's to replace the trigger bar today (this VP9 has always had a hiccup in the trigger press, now gone, must have been an out of spec trigger bar).
Damn thing is typical German over-engineering, why use one part when you can use three to do the same thing.
Just like a Matryoshka doll, you have a pin inside a spring inside another pin and spring.
And I do wish H&K would come up with a new trigger return spring design, their legacy setup of a tensioned torsion spring held in place by the slide stop/trigger axle is and always has been a pain in the ass to install.
That is all.