Some shoot with a full cover sight, meaning what the front site covers is where the projectile will hit, other use a modified 6 o'clock hold where the front sight covers part of where the target will be hit. Normally they like the bullet to hit right at the top of the sight. Then as you describe, there is the 6 o'clock hold where the bullet strikes right on the top of the front sight.

I normally like a modified hold but have been shooting many with aopen 6 o'clock hold and it is working real well... Good advise sproulman.