RE: 6 o'clock hold
The 6 oclock hold is really only for target shooting only. For a hunting/plinking/defensive handgun, the sights need to be set so that the point of impact = point of aim (point of aim being the top edge of the front sight on a standard black front balde sight). With some of the combat type pistol sights, the sights are set so that cover the target with or put the target on top of a white or glowing triangle or dot.