RE: pistol shooting----low
You know I had a bunch of issues shooting pistols. I ended up finding the Army instruction manual on pistol shooting, and there was some great info in it for various issues like you got. Most likely you are gripping the gun right at the shot. Hard to see unless you work with a partner blank load practicing. If that tip falls, on the time there is no round in there, it tells you your problem.
If you are solid during the shot, then might want to look into the way you are using your front post.