When ever I shoot my pistols, the first mag that I shoot my heart races and my arm twitches. After the first mag, I settle down. I don't know what it is. I have been shooting now for over a decade, have owned about a dozen pistols, and for a while I was shooting pretty regularly. I have always been this way.
I don't get the same thing with my rifles or shot guns.
About the only time that I don't have this happen with pistols is when I am shooting out doors. Other people that I know that shoot are the same way. I was curious if anyone here was like that too, or knew what was goign on.
I get like that on the first stage at matches. Hands sweaty, heart pounding in my ears. I keep saying over and over in my head, "slow but accurate, front sight, front sight", Then the buzzer goes off and I blast away anyways.
My first shot is almost always dead on and the mag thereafter I'm solid.
I just let my body do the work muscle memory et. al.
What does happen though is after an hour or so I begin to progressively get worst from tiring or over thinking with too much effort concentratiing. Thats when the shakes kick in and I begin second guessing my sight picture, trigger depression versus pull, finger placement, grip, stance...everything. I'd end up walking away with a target that looks like a straight up beginner versus those earlier.
What I've learned to do is just not shoot more than 150 rounds per training session or 1 hr. max, which ever comes first.
Quality versus quantity. Shoot for an hour then come back later in the week and shoot again for an hour is, for me, more productive than one session of even 1.5 hrs. or running through 200 rds. or more.
I have the same problem when training for tournament paintball, half day mini drill sessions (2 hrs) are more productive for me than a full day of constant drills & rotations.
Overly oncentrating takes a real performance toll at least for me.