I am new to this forum and appreciate being able to join it. i recently purchased a glock 27 and if I line the sights up level i shoot really low at 10 yards. I also have a .45 Kimber that I line the front sight up even with the back sight and it hits perfectly out to 20 yards so I expected that with my Glock. At 10 yards in order to be accurate I have to place the front sight dot above the rear sight. It looks like a ball sitting on a shelf. This is my first glock so I am unfamiliar with the intricacies of the weapon. It is fixed site...so my question is....is it me? Can I purchase a taller rear sight to install? I certainly am no handgun expert....the aiming is just different from what I have ever done with any of my weapons. I appreciate any advice or recommendations.