What I did was to set the external adjustment so that it was at 3.5 pounds (the factory setting), then adjusted the adjustment screw (the one with the red arrow pointing to it in the picture. leftie loosie, rightie tightie. Mine is now set at a nice reliable 40 oz. pull, with no slam fires. If you adjust yours, make sure it doesn't release when you slam the butt on the floor.
Weight adjustment screw is on the trigger face. I can turn the screw all the way out counterclockwise until it falls out and it is 3 1/2lbs. I had no problem adjusting the regular x-mark pro trigger just like any other 700 trigger. I think some people are confusing the new trigger that came out in 2009 with the 2007 x-mark pro trigger
