I'm taking my time, lowering the weapon and resting it between shots, watching my breathing, natural point of aim, try to be as cognizant of trigger control as possible. I'm seeing the muzzle flash and following the front sight. I've been mostly running a 229R in 9mm but it's happening with my Ruger MKI that I bring with me to keep down ammo costs too. So I don't think it's the weapon. I'm not a "new" pistol shooter, but I've never been stellar and am trying to improve. I guess I need to take the 1911 out, never had this problem with it.
I've recently adjusted my grip somewhat, switching from primarily shooting a 1911 to the Sig. High thumb on a Sig means that sometimes you don't get slide lock. But I can sit here and dry fire forever and the sight picture looks good when the trigger breaks. I dunno, maybe I'm thinking about it too much at 25 and am anticipating just slightly, maybe both pistols are shooting low right...
Something else: I've recently been concentrating on shooting with both eyes open. I did it with one eye for years and have kinda been half ass converting for a while, but have really been concentrating on it now. Dunno if that could make a difference. Maybe I need to go back to the Vaseline smear....