Hi. 'Breaking the wrist' means you're relaxing your hand too soon. Vertical at 1 o'clock is about anticipating the recoil. What ammo? About 15 yards or at 15? Where are you aiming? Consistency, in everything shooting related, matters.
Mind you, a consistent 4" group isn't ugly. Isn't a bullseye target group, but neither is Glock 22 isn't a target pistol either and you're good enough to defend yourself. The grips may be a bit to big or too small as well. Not likely though. Groups are too consistent.
You think too. That's more important than anthing else. Try some lighter recoiling ammo.
Go here and download the free Lee 'Target Left or Right handed, .pdf. Sounds like you have it already though.
http://www.reloadbench.com/pdf.html