Very common for right handed shooters. If it wasn't clear to you from what others have already said about anticipation, an alternative explanation (humorous) was described as you "getting assistance from the three amigos". This refers to the middle, ring, and pinky fingers on your strong side hand. You anticipate the pistol will recoil, and you "want" to keep in on target, so you grip with these three fingers a little harder just before you expect the trigger to break. This drags the muzzle down and left as the round goes off. This is more pronounced if you "decide" to pull the trigger NOW, and then quickly pull the trigger (slapping). As others have said, practice pressing the trigger and not moving the sight during dry fire. build muscle memory doing that. Practice pressing the trigger slowly and smoothly. The trigger break should come as a surprise to you when doing this. Put more concentration into gripping the pistol with your support hand so you can somewhat relax the strong side hand (especially those three amigos). The tighter you grip with your strong hand, the more pronounced the effect of the three amigos when you anticipate the shot. As others have already said, practice with a .22 also helps as you simply have less recoil to anticipate. Good luck!