I strongly suggest that you do not move the sight without considering these thoughts.
Being short, pistol sight radius is an extremely important factor of accuracy. Hers is a quote of a linked article about the affect of sight radius on accuracy.
[/QUOTEAs noted above, a mere half a millimeter on a 3” sight radius produces a sighting error of almost 3” at 25 yards, while a Thompson/Contender with nearly a 15” sight radius is only off about 6/10th of a inch at the same range.
Consider that a half a millimeter is is about 1/50th of an inch. Consider the space between the front blade sight nd the rear notch sight. There is room for a 1/50th inch error. Your sights might be fine. Exactness of aiming is human so error is the norm.
Unless you can bench test the pistol with a proper stabilizing device and confirm the left drift, I would first assume that the error is in aiming or trigger pull. Assuming you are right handed placing the trigger to the right of the center of the first digit pad will pull the gun to the right. Placing it too close to the fingertip will pull the gun to the left. Get it centered and with exact blade alignment I will bet. your P1 will be on center. Theory is wonderful, but now practicality comes in.
I qualified as expert marksman with the M1911A1 in the Corps. It was my primary weapon and I was hellbent on being accurate with it. I continually shot to the right during initial training. When I told my instructor that the sights were off in typical Marine NCO fashion he asserted that he would fix it by moving my eye. He told me about finger position on the trigger as mentioned above. Trial, error, and practice had me shooting on center in a day.
The M1911 like the M9 and M17 hd a maximum effective range of 50 meters. But what that spec does not tell you is that it dan hard to achieve accuracy at 25 meters with a pistol with a 5 inch barrel. At that distance we were trained to use aim point adjustment to get on center. Hitting to the right means aiming to the left to correct. Of course we were learning combat oriented shooting not target shooting. The P1 is not a target pistol. It is a CQB pistol. Shift your aim point.
What started as a simple side grip replacement became a lesson on paying attention (or not) as the trigger bar fell out and I cannot determine how to engage the trigger bar with the trigger bar spring. This is frustrating to be looking right at something and not arriving at a...