I have two semi-auto pistols. A Ruger MK II (.22lr) and a Beretta 92F (9mm). They both have factory iron sights. The Ruger has plain metal sights with no paint or markings, a blade up front and a notch at the rear. With this pistol I can consistently shoot groups 3" or so at 15-20 yds, using both hands, unsupported. The Beretta has a blade up front with a white dot, and and a notch at the back with a white dot centered below the notch. With this pistol I can keep all shots on a paper plate at 15-20yds... It's easy to keep the tops of the notch and blade even (level) on the .22, but on the 9mm it's difficult to keep them aligned... it requires tremendous concentration to avoid shooting high or low. Even with that, though, there's considerable variance left to right. For perspective, I've put about 500 rds through the .22, and only 150 or so through the 9mm. Maybe I just haven't shot it enough to get a good picture in my mind, or a repeatable consistent trigger pull... but I think maybe changing the rear sight would help. Any input?