Lewis had some good advise.
Also, how heavy is the pull? Sounds like a heavy pull, before we changed triggers on my buddy's Ruger it was so heavy you had to keep checking to see if the safety was all the way off.
If it's a bolt action, try not wrapping your thump around and gripping. When you do wrap your thumb you can have a tendency to squeeze with your whole hand and not come straight back with on the trigger.
Or you could be anticipating the shot.
Courage is just fear that has said it's prayers.
The people trying to say the 2nd Amendment is outdated are probably the same folks that would say the same thing about the Bible.