Practice with your preferred rifle builds confidence in making the shot.
I made my 2nd longest shot on a buck this year - 259 yards as determined with a laser rangefinder (before I took the shot.).
I had practiced with the rifle at 100, 200, and 300 yds. from a steady rest, but from range positions. The rifle is a true MOA or less shooter and I knew I could/would make the shot - provided I had a good, solid rest.
I dropped the buck in his tracks.
THEN I got the shakes! LOL!