Hello oldmanriver,
As you can see in the photo above, each trigger has a small screw for adjusting the "set-sear" engagement. When you pull the triggers normal, each trigger has about 4 to 5 pounds of pull.
To "set" the triggers, you push them "forward" and they "click" in place. The "set-sear" locks them forward about 1/8". Now when you touch the triggers, they have only 4 to 5 "ounces" of pull.
The whole idea of a set trigger is that if you have a lot of time, to take careful aim, (say at a longer than typical distance) a "hair" trigger eliminates much of the "gun wiggle" that comes from pulling a heavier trigger.
I have another German double that also has a "set" trigger, but it only has one, the front trigger for the right barrel.
Apparently with this Kettner, the idea is to "set" the front trigger, shoot the right barrel, then "set" the rear trigger, and shoot the left barrel - one at a time - and NOT to set both at once.
