Harder to decsribe than show you, but your trigger PRESS should be straight back. When you jerk the trigger, the gun tends to move right (r hand shooter) when you pull the trigger instead of press, it tends to push the shot left, usuall low, but high left is often anticipation of recoil as you pull the trigger.I shoot high and left.
I'm not sure what "pushing the trigger" means.
I shot 100 rounds yesterday morning at a new steel zombie target I made. I did not notice my support grip being anything excessive.
I do know that I typically fire before I aim the sights. In other words I point the barrel at the target but I do not close one eye, line up the three dots, and slowly squeeze the trigger. That just takes too long and takes away too much of my sight picture. I hit the target, 75% of the time. When I do slow down and aim obviously my shots are much more precise, but is that real world shooting? Seems to me if I can hit a silouhete (sp?) target 75 % of the time and feel more comfortable in my position than taking the time to precisley aim, then I may be better off. Off course I would like my accuracy to improve, which is why I am in this forum and why I practice.
I'm not sure if continuing to practice will cure my high left shooting, or if there is a fundamental that I need to go back, relearn and correct.
If I could only hit a sil 75% of the time @ full speed @ 21ft, I would be practicing a lot more. That just isn't acceptable. Only hits count, so if you have to slow down a nano second to get at least the front sight on the target, so be it. Slow down, go for accuracy, trigger control first. The speed will come. If you can't hit it, then it matters little how fast you shoot at it. The old saying is speed is fine but accuracy is final.
Example, when I shoot doubles or controled pairs, if they are touching, then I am shooting too slow. If they are more than 5-6" apart, a bit too fast. Hits are all that matter regardless of speed. Yo ucan NOT miss fast enough to win a fight.