with the JT, there is no adjustment screw
I tried adjusting my JT 6 a while back. take a look at how kingman tried it, they tapped a screw into the top of the trigger at the front inside the frame, to make the trigger start point closer. however, you can easily out-shoot the JT's board with the trigger set up as it is, I wouldn't bother, put it down, try and sell it, and buy something better...
Zwit