Hello... When I went shooting yesterday, I noticed my groups are slightly left of where I'm aiming.
I'm doing something fundamentally wrong if I'm grouping left?
When we pull/press with the trigger finger, we often/sometimes sympathetically move third, fourth and fifth fingers and if you are a right handed shooter, will push on the pistol grip to move point of impact (POI) to the left of point of aim (POA).
To test this, clear your pistol and dry fire while watching the front sight. Are you pushing the front sight when the hammer/striker is released? And at the range, place your target at 5-7 yards and align the sights on a small dot on target. Now close your eyes and fire and repeat several times shooting with eyes closed after sight alignment on the dot. Did POI deviate to left of POA? And are you doing that on a consistent basis?
And as Brian Zins explains at 2:00 minute of video below, your trigger control (Or lack of) could be moving the front sight to the left of POA just before bullet exits the barrel. We had a quite extensive and detailed discussion in ST&T on trigger control here -
https://www.thehighroad.org/index.php?threads/trigger-control.834737/page-3#post-11255509
"You can hold sight alignment and sight picture on your pistol all day long. When does it change?
When you move the trigger. Sights move. They are going to move. They have to move.
... No matter how big your hands ... strong you are ... death grip ... as soon as you apply force ... on this pistol, it's going to move"
Note at 1:58 - 2:02 he says: "...there is no sense working on your stance, your position, your grip if you can't pull the trigger without disturbing the sights, so trigger control is key"
The stance/grip/pistol together is in a state of dynamic motion to counteract/compensate for trigger pull/press to keep sight alignment on Point of Aim (POA) so Point of Impact (POI) will occur at the same spot, regardless whether using two hands, one strong/weak hand, two fingers (thumb/middle finger), sighted/unsighted, slow-fire bullseye, or rapid-fire action pistol.
If the shooter does not apply consistent trigger control, regardless of the stance/grip used, muzzle/front sight of the pistol will move just before the bullet exits the barrel and POI will deviate from POA.
Now, if you are grouping left with just one pistol and the pistol has sufficiently broken in (trigger surfaces have smoothed out) and grouping is tight, you can drift the rear sight.