If the military team shoots an M14 or M16 in Service Rifle, you get an M1A or AR15, semiauto only and legal for an American to own... so far.
It is hard to argue against a .22. As Jeff Cooper said, "you can learn about 80% of what you need to know with a .22."
Shoot it at 50 yards to develop technique, then move out to get practice in judging the wind comparable to a centerfire at longer range.
A good .22 at 100 yards is a challenge. At 200 it is darned tough.
Service life of a .22 barrel is very long, you will not wear it out and can always go back to it for quiet economical practice.
A friend shoots F-class, at 1000 yards by choice, but he shoots a pellet gun in the basement every day and a .22 in the back yard several times a week.
He wins with the big gun, too.