What distances are handguns zero'ed in at? And what distances are the sights of different rifles out there set for? I noticed my Glock 30 factory sights make the barrel point slightly upwards when the sights are leveled. I saw this when I placed my Glock upside down on a flat surface and the space beween the front end of the slide and the counter that i used is ever so slightly less then the back end of the slide to the flat surface. This is assuming the barrel is parallel with the top of my slide. At what distance do the line of sight cross the path of projectile travel if gravity (9.8 m/s squared) is taken out of the equation?