I haven't fired a handgun since I was 16 (which was 16 years ago), but my father-in-law took me to the range today. Besides losing some of the skin on my thumb to a Glock breach, I think I did alright. I put 50 rounds through a Charter Arms .38 snub nose revolver and 50 through a first-generation Glock 9mm.
Decent grouping for center mass.
Take it from a Class 2 & 3 L.E. firearms instructor and graduate of the Ft. Benning Sniper School... to close in the vertical stringing, watch your breath control. Breathing during the final stage of trigger advancement will cause that or waiting too long after the stop/hold (breath in, half out & hold) will also. After a few seconds of not breathing the heart will start beating harder and the transmitted core vibrations will be amplified to the hands. The sight alignment/trigger advancement/breath hold should be all be in synch.
Raising the hand on the grip will tighten this up too if the top part of the web between the thumb and forefinger is not properly indexed..
Milking the grip (squeezing with the whole hand instead of just the trigger finger) will also. Make sure that once the grip is established nothing changes except the trigger finger. No changes in the pressure of the rest on the hand/fingers.
Assuming a right hand grip, the group can be centered back left (the sights are properly aligned?) by adding a little more trigger finger. Make sure the trigger finger is pulling straight back. Too little finger engagement with the trigger lever will cause the finger to "curl out" putting pressure on the side of the lever causing right movement during recoil; the opposite, too much finger if shooting left hand will cause a right drift.
Not trying to criticize, just trying to help. The better you shoot the better you want to shoot.
50% of shooting is 95% mental preparation.
Great overall. I wouldn't want them holes in me
Keep up the good work. Just try to get that vertical string in more of a circle