If you have a TO-5 trigger, there's only one screw to adjust. Backing it out, counter clockwise, lengthens the first stage and lightens the second stage. If the gun is new, the screw can be really tight at first. On my 350, it was screwed all the way in when I got it. Bear in mind, if you keep backing it out, you will totally eliminate the second stage. Also, I've found that with the trigger adjusted close to that point, the adjustment can shift. Since I like a very light trigger, I've got mine set right on the edge of no second stage, so I have to readjust it fairly frequently. HTH.
Thanks Dave - but I've got two screws. So far as i can work out, one works the end of the internal trigger lever, and the other works the inner part - hence really a three part trigger - the first just the spring, the second as the outer screw starts to move the internal lever, and the third as the second screw completes the movement.
I guess I can just fiddle with these until it feels right - I'm pretty close to that now - but one presumes that there would be an "approved" method for doing so.
Sorry, Mark, can't help you directly, but maybe this will help: http://www.eddiecolwell.tzo.com/RWS-54.htm
Even though his site is all about the 54, the trigger is the same, and he has a really good section on it. Just keep scrolling down the page. Hope this helps, and good luck.
Mark, I don't own any modern Dianas with the "T 01" trigger, but I believe it is basically the same as the ball-sear unit in the older guns like the model 27 and 35.
On those guns, there are two screws, but only one true adjustment. The front screw is simply a locking device for the true adjuster screw, the rear one. This adjusts the point where the first stage of the trigger pull changes to the second stage (you CANNOT directly adjust the pull weight, or total length of the pull; only the transition point). When correctly set, of course you should feel the second stage "kick in" just before the trigger releases.
So the procedure is: 1) turn front screw out (i.e. counterclockwise) 2) turn rear screw in for longer second stage, or out for shorter second stage 3) when happy, turn front screw back in until firm.
On the old guns the adjuster screw has a great deal of movement range. It is possible to make the trigger pull either "all first stage" (i.e. it goes off before you get to the second stage), or "all second stage" (long heavy gritty pull without a light take-up stage). You can't really make the trigger unsafe on these guns since the adjustment doesn't affect sear engagement, so it can be interesting to experiment with. But when you get to that short crisp second stage, there's really nothing else you can do to it...time to quit fiddling with the trigger and go shoot!