Back to BlueTrain's comment about shooting a lot in one session, I found some years ago that after shooting some number--750, maybe, but I cannot recall--of rounds in a high performance pistol shooing course, I reached a plateau, and stopped improving.
I was using a steel framed .45 automatic. Had I been shooting a light gun, I would have had another problem. BlueTrain mentioned shooting 100 rounds in one session being "hard on your hand". The fact is, too much shooting at one time with a light handgun can lead to irreversible damage to tendons, joints, and nerves. The damage is cumulative. I limit my shooting for that reason. There was a time that I did not. That was a mistake--a bad one.
For those to and three day courses, you really do want to use a service size pistol, and consider wearing gloves. But at least in my experience, I do tend to reach a plateau after some number of rounds, and after that more is not better, but worse.