Any suggestions?

[wtretrievers]

I have acquired a 13 year old for youth w/e this coming w/e in Mississippi, & he hasn't had much experience shooting, something I'm not used too. My 2 boys are 15 & 17 & have been shooting since they were very young.

The problem is I had him shooting a .22 this past w/e & he is right eye dominate & left handed. So when he shoots he puts the rifle on his left shoulder & leans his head over & looks through his right eye. He could group consistent at 40 yards, just worried when a .243 or bigger in his hands to hunt with it is going to bust his azz! Don't have time to switch him over & get him used to shooting the correct way.
I tried to get him to shoot through his left eye but he had trouble, also off his right shoulder & it's uncomfortable, I know he needs seat time.

Any suggestions??????