Originally Posted by kouye
Okay. So I set up my K31 according to swissrifles.com site and I'll tune the rear tang screw while I'm at the range. We'll see if it makes a difference.
Better don't do that, it can cause cracks in the trigger assembly housing. First the front screw dead tight and second the tang screw.
When playing with the tang screw is reducing your group size there is something wrong with the bedding at the front end of the receiver. To adjust the front end height of the receiver the Swiss use shims that come in four thickness sizes and they are inside the stock at the spot where the front receiver screw enters. Adjusting is done by taking out or adding shims.
Remember that these rifles are 60 or more years old and so is the wood of the stocks, wood tends to work and deform over the years and that makes a re-adjustment pretty normal.