RE: 6 o'clock hold
The six o'clock hold means you put the entire "target area" on top of the front sight. And the front sight is not set down into the notch of the back sight, it is level with the back sight.
So if you are shooting a can-what part is the target. The entire can?? Or the center of the can??
Actually the back sight is as important as the front sight when shooting this hold. You are not trying to set the front sight down into the notch, you need to keep them both level.
I use this hold for revolver and pistolopen sights. By shooting this way it allows you to visualize the entire target. I prefer that. Tom.