Can someone with a factory rear sight possibly take a measurement for me??? What I am looking for is the measurement from the top of the barrel to the bottom of the rear sight notch in mm. and what range their gun is setup for at that height. I have no factory rear sight otherwise I would do it myself. I am working on adapting a much nicer rear fully adjustable sight install and need this before I proceed to make sure it will go down as low as the factory rear sight. Thanks, Jeremiah.