Does the gun have an auto-safe?
If so, is that pivoting/moving plate what resets the Safe when the action is opened.
If it is then maybe with the screw too tight, the plate can't come back forward all the way after the action is closed.
That might leave the auto-safe bar still to the rear slightly & in partial contact with the safety mechanism/linkage itself.
Perhaps making for the tough pull on one of the triggers.
Things don't always (usually) line up inside a SXS the same way when put together with the stock on as with the stock off.
Tangs flex, screws turned a 1/4 turn one way or the other can make a difference in safety, sears and triggers working well or not at all.
It may work fine one way and not the other.
One of the tough things about fixing single trigger guns, you can't see what's really going on inside there.
Just some thoughts..
