From the look of your target it appears that a number of things are happening. The 6:00 hits are indicative of what happens when the trigger is pulled right through without taking up the slack before it breaks. I am also willing to bet you watching your bullet impacts, and attempting to make sight adjustments from them. That's akin to chasing your zero in rifle shooting, and like chasing your zero will result in strung out groups. Generally speaking though, a group that runs out from center at 8:00 is the result of squeezing the base of the grip frame with the bottom two fingers. This is why we are incorrect when we say squeeze the trigger, as one squeezes with his entire hand, what we mean to say is that the trigger is pressed with only the trigger finger, the movement being straight back.
Dry firing will reveal problems you cannot see when live firing. When the hammer falls, what the front sight covers is what you will hit. But knowing where you bullet is hitting isn't much help unless you know how to correct it, and that is why it is important to have a really good shooting coach.