You may want to see if you can find some military field manuals on marksmanship, ebay or surplus store, good info in them, help both you and him, rationale is they schooled masses of people on how to accomplish results, will have all the positions, good reference material at least and should be easy to source, he may need to grow a bit, but sooner or later he will figure it out. I remember the first time I shot a .22, was in first grade, was a rifle, I could barely hold it up in a standing position, relaxed down to a hip just to get the feel of it, my dad was always busy, or short on time, was a friend of moms over for dinner husband and wife, he brought a .22 rifle to plink with after, I thought that was really cool, as there was no way my dad would have done this, they were not cool about anything actually LOL, but the opportunity to shoot and the experience was priceless. Years later I pressed him on it, went out a few times, that was it, figured it out on my own and I used military manuals, from school, as it had a JROTC program, had a rifle team and a tactical team, qualified at the National Guard range with the M16, anf 1911 .45 starting as a freshman, that was good stuff in those days ! Junior and Senior years, we went to one of the ranges at West Point, if we learned nothing else, we sure learned some marksmanship.
Like was said below, practice and practice again, might get tired or just off if too much, knock off, try again asap, the bench ought to build confidence for the other positions, not easy, I remember how heavy that rifle was to me then, nice experience for a father to teach a son marksmanship, and SAFETY, too ! Be good to hear back in a few weeks, bet he improves too !!!
