I recently bought an Axis HB in .223 and I decided to do the "pen spring" trigger mod. So I screw out the factory spring and use the pen spring and a 10-24 set screw. I get it down to where it checks 3.5lbs on my trigger scale and passes the hammer test while it's outside the stock. So I put the action back in the stock and test again and the trigger pull is now 6lbs.

To make a long story short after playing with it for awhile I've come to realize the more I torque the back action screw the higher the trigger weight go's.
Has anyone seen this correlation between the action screw and trigger weight before? I also see that there is a spring between the trigger housing and the action. Could I replace that with a shim and still be able to torque my action screw and keep my trigger weight at 3.5lbs?